diff --git a/1-js/03-code-quality/05-testing/3-pow-test-wrong/solution.md b/1-js/03-code-quality/05-testing/3-pow-test-wrong/solution.md
index 31f193ac..e4c94ed8 100644
--- a/1-js/03-code-quality/05-testing/3-pow-test-wrong/solution.md
+++ b/1-js/03-code-quality/05-testing/3-pow-test-wrong/solution.md
@@ -1,8 +1,12 @@
-Этот тест демонстрирует один из соблазнов, которые ожидают начинающего автора тестов.
+The test demonstrates one of temptations a developer meets when writing tests.
 
-Вместо того, чтобы написать три различных теста, он изложил их в виде одного потока вычислений, с несколькими `assert`.
+What we have here is actually 3 tests, but layed out as a single function with 3 asserts.
 
-Иногда так написать легче и проще, однако при ошибке в тесте гораздо менее очевидно, что же пошло не так.
+Sometimes it's easier to write this way, but if an error occurs, it's much less obvious what went wrong.
+
+If an error happens inside a complex execution flow, then we'll have to figure out what was the data at that point.
+
+TODO
 
 Если в сложном тесте произошла ошибка где-то посередине потока вычислений, то придётся выяснять, какие конкретно были входные и выходные данные на этот момент, то есть по сути -- отлаживать код самого теста.
 
diff --git a/1-js/03-code-quality/05-testing/3-pow-test-wrong/task.md b/1-js/03-code-quality/05-testing/3-pow-test-wrong/task.md
index 7c8b60b2..6f090cb6 100644
--- a/1-js/03-code-quality/05-testing/3-pow-test-wrong/task.md
+++ b/1-js/03-code-quality/05-testing/3-pow-test-wrong/task.md
@@ -2,23 +2,23 @@ importance: 5
 
 ---
 
-# Что не так в тесте?
+# What's wrong in the test?
 
-Что не так в этом тесте функции `pow`?
+What's wrong in the test of `pow` below?
 
 ```js
-it("Возводит x в степень n", function() {
-  var x = 5;
+it("Raises x to the power n", function() {
+  let x = 5;
 
-  var result = x;
+  let result = x;
   assert.equal(pow(x, 1), result);
 
-  var result *= x;
+  result *= x;
   assert.equal(pow(x, 2), result);
 
-  var result *= x;
+  result *= x;
   assert.equal(pow(x, 3), result);
 });
 ```
 
-P.S. Синтаксически он верен и работает, но спроектирован неправильно.
\ No newline at end of file
+P.S. Syntactically it's correct and passes.
diff --git a/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/solution.md b/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/solution.md
index f875fca0..79a29b0d 100644
--- a/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/solution.md
+++ b/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/solution.md
@@ -1,18 +1,14 @@
-Да, возможны.
+Yes, it's possible.
 
-Они должны возвращать одинаковый объект. При этом если функция возвращает объект, то `this` не используется.
+If a function returns an object then `new` returns it instead of `this`.
 
-Например, они могут вернуть один и тот же объект `obj`, определённый снаружи:
+So thay can, for instance, return the same externally defined object `obj`:
 
 ```js run no-beautify
-var obj = {};
+let obj = {};
 
 function A() { return obj; }
 function B() { return obj; }
 
-var a = new A;
-var b = new B;
-
-alert( a == b ); // true
+alert( new A() == new B() ); // true
 ```
-
diff --git a/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/task.md b/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/task.md
index 287bfc1f..aacb6258 100644
--- a/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/task.md
+++ b/1-js/04-object-basics/06-constructor-new/1-two-functions-one-object/task.md
@@ -2,9 +2,9 @@ importance: 2
 
 ---
 
-# Две функции один объект
+# Two functions -- one object
 
-Возможны ли такие функции `A` и `B` в примере ниже, что соответствующие объекты `a,b` равны (см. код ниже)?
+Is it possible to create functions `A` and `B` such as `new A()==new B()`?
 
 ```js no-beautify
 function A() { ... }
@@ -16,4 +16,4 @@ var b = new B;
 alert( a == b ); // true
 ```
 
-Если да -- приведите пример кода с такими функциями.
\ No newline at end of file
+If it is, then provide an example of their code.
diff --git a/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/_js.view/test.js b/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/_js.view/test.js
index ef881c45..03605392 100644
--- a/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/_js.view/test.js
+++ b/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/_js.view/test.js
@@ -1,25 +1,25 @@
-sinon.stub(window, "prompt")
-
-prompt.onCall(0).returns("2");
-prompt.onCall(1).returns("3");
 
 describe("calculator", function() {
-  var calculator;
+  let calculator;
   before(function() {
+    sinon.stub(window, "prompt")
+
+    prompt.onCall(0).returns("2");
+    prompt.onCall(1).returns("3");
+
     calculator = new Calculator();
     calculator.read();
   });
 
-  it("при вводе 2 и 3 сумма равна 5", function() {
+  it("when 2 and 3 are entered, the sum is 5", function() {
     assert.equal(calculator.sum(), 5);
   });
 
-  it("при вводе 2 и 3 произведение равно 6", function() {
+  it("when 2 and 3 are entered, the product is 6", function() {
     assert.equal(calculator.mul(), 6);
   });
 
+  after(function() {
+    prompt.restore();
+  });
 });
-
-after(function() {
-  prompt.restore();
-});
\ No newline at end of file
diff --git a/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/solution.md b/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/solution.md
index bbff1040..e5583c5d 100644
--- a/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/solution.md
+++ b/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/solution.md
@@ -17,10 +17,9 @@ function Calculator() {
   };
 }
 
-var calculator = new Calculator();
+let calculator = new Calculator();
 calculator.read();
 
-alert( "Сумма=" + calculator.sum() );
-alert( "Произведение=" + calculator.mul() );
+alert( "Sum=" + calculator.sum() );
+alert( "Mul=" + calculator.mul() );
 ```
-
diff --git a/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/task.md b/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/task.md
index 54f844c9..60e7c373 100644
--- a/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/task.md
+++ b/1-js/04-object-basics/06-constructor-new/2-calculator-constructor/task.md
@@ -2,23 +2,22 @@ importance: 5
 
 ---
 
-# Создать Calculator при помощи конструктора
+# Create new Calculator
 
-Напишите *функцию-конструктор* `Calculator`, которая создает объект с тремя методами:
+Create a constructor function `Calculator` that creates objects with 3 methods:
 
-- Метод `read()` запрашивает два значения при помощи `prompt` и запоминает их в свойствах объекта.
-- Метод `sum()` возвращает сумму запомненных свойств.
-- Метод `mul()` возвращает произведение запомненных свойств.
+- `read()` asks for two values using `prompt` and remembers them in object properties.
+- `sum()` returns the sum of these properties.
+- `mul()` returns the multiplication product of these properties.
 
-Пример использования:
+For instance:
 
 ```js
-var calculator = new Calculator();
+let calculator = new Calculator();
 calculator.read();
 
-alert( "Сумма=" + calculator.sum() );
-alert( "Произведение=" + calculator.mul() );
+alert( "Sum=" + calculator.sum() );
+alert( "Mul=" + calculator.mul() );
 ```
 
 [demo]
-
diff --git a/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/solution.js b/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/solution.js
index bd744597..585287c5 100644
--- a/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/solution.js
+++ b/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/solution.js
@@ -2,7 +2,7 @@ function Accumulator(startingValue) {
   this.value = startingValue;
 
   this.read = function() {
-    this.value += +prompt('Сколько добавлять будем?', 0);
+    this.value += +prompt('How much to add?', 0);
   };
 
-}
\ No newline at end of file
+}
diff --git a/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/test.js b/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/test.js
index aa651b11..a719cf45 100644
--- a/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/test.js
+++ b/1-js/04-object-basics/06-constructor-new/3-accumulator/_js.view/test.js
@@ -1,8 +1,4 @@
-describe("Accumulator(1)", function() {
-  var accumulator;
-  before(function() {
-    accumulator = new Accumulator(1);
-  });
+describe("Accumulator", function() {
 
   beforeEach(function() {
     sinon.stub(window, "prompt")
@@ -12,26 +8,23 @@ describe("Accumulator(1)", function() {
     prompt.restore();
   });
 
-  it("начальное значение 1", function() {
+  it("initial value is the argument of the constructor", function() {
+    let accumulator = new Accumulator(1);
+
     assert.equal(accumulator.value, 1);
   });
 
-  it("после ввода 0 значение 1", function() {
+  it("after reading 0, the value is 1", function() {
+    let accumulator = new Accumulator(1);
     prompt.returns("0");
     accumulator.read();
     assert.equal(accumulator.value, 1);
   });
 
-  it("после ввода 1 значение 2", function() {
+  it("after reading 1, the value is 2", function() {
+    let accumulator = new Accumulator(1);
     prompt.returns("1");
     accumulator.read();
     assert.equal(accumulator.value, 2);
   });
-
-  it("после ввода 2 значение 4", function() {
-    prompt.returns("2");
-    accumulator.read();
-    assert.equal(accumulator.value, 4);
-  });
-
-});
\ No newline at end of file
+});
diff --git a/1-js/04-object-basics/06-constructor-new/3-accumulator/solution.md b/1-js/04-object-basics/06-constructor-new/3-accumulator/solution.md
index f348cdc2..eb145e79 100644
--- a/1-js/04-object-basics/06-constructor-new/3-accumulator/solution.md
+++ b/1-js/04-object-basics/06-constructor-new/3-accumulator/solution.md
@@ -5,14 +5,13 @@ function Accumulator(startingValue) {
   this.value = startingValue;
 
   this.read = function() {
-    this.value += +prompt('Сколько добавлять будем?', 0);
+    this.value += +prompt('How much to add?', 0);
   };
 
 }
 
-var accumulator = new Accumulator(1);
+let accumulator = new Accumulator(1);
 accumulator.read();
 accumulator.read();
-alert( accumulator.value );
+alert(accumulator.value);
 ```
-
diff --git a/1-js/04-object-basics/06-constructor-new/3-accumulator/task.md b/1-js/04-object-basics/06-constructor-new/3-accumulator/task.md
index 3bd5b5a0..3362b5b4 100644
--- a/1-js/04-object-basics/06-constructor-new/3-accumulator/task.md
+++ b/1-js/04-object-basics/06-constructor-new/3-accumulator/task.md
@@ -2,26 +2,24 @@ importance: 5
 
 ---
 
-# Создать Accumulator при помощи конструктора
+# Create new Accumulator
 
-Напишите *функцию-конструктор* `Accumulator(startingValue)`.
-Объекты, которые она создает, должны хранить текущую сумму и прибавлять к ней то, что вводит посетитель.
+Create a constructor function `Accumulator(startingValue)`.
 
-Более формально, объект должен:
+Object that it creates should:
 
-- Хранить текущее значение в своём свойстве `value`. Начальное значение свойства `value` ставится конструктором равным `startingValue`.
-- Метод `read()` вызывает `prompt`, принимает число и прибавляет его к свойству `value`.
+- Store the "current value" in the property `value`. The starting value is set to the argument of the constructor `startingValue`.
+- The `read()` method should use `prompt` to read a new number and add it to `value`.
 
-Таким образом, свойство `value` является текущей суммой всего, что ввел посетитель при вызовах метода `read()`, с учетом начального значения `startingValue`.
+In other words, the `value` property is the sum of all user-entered values with the initial value  `startingValue`.
 
-Ниже вы можете посмотреть работу кода:
+Here's the demo of the code:
 
 ```js
-var accumulator = new Accumulator(1); // начальное значение 1
-accumulator.read(); // прибавит ввод prompt к текущему значению
-accumulator.read(); // прибавит ввод prompt к текущему значению
-alert( accumulator.value ); // выведет текущее значение
+let accumulator = new Accumulator(1); // initial value 1
+accumulator.read(); // adds the user-entered value
+accumulator.read(); // adds the user-entered value
+alert(accumulator.value); // shows the sum of these values
 ```
 
 [demo]
-
diff --git a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/solution.js b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/solution.js
index e2942e02..50c40e80 100644
--- a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/solution.js
+++ b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/solution.js
@@ -1,17 +1,13 @@
 function Calculator() {
 
-  var methods = {
-    "-": function(a, b) {
-      return a - b;
-    },
-    "+": function(a, b) {
-      return a + b;
-    }
+  let methods = {
+    "-": (a, b) => a - b,
+    "+": (a, b) => a + b
   };
 
   this.calculate = function(str) {
 
-    var split = str.split(' '),
+    let split = str.split(' '),
       a = +split[0],
       op = split[1],
       b = +split[2]
diff --git a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/test.js b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/test.js
index 2c6891a9..eac4f54a 100644
--- a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/test.js
+++ b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/_js.view/test.js
@@ -1,26 +1,25 @@
-var calculator;
-before(function() {
-  calculator = new Calculator;
-});
+describe("Calculator", function() {
+  let calculator;
 
-it("calculate(12 + 34) = 46", function() {
-  assert.equal(calculator.calculate("12 + 34"), 46);
-});
-
-it("calculate(34 - 12) = 22", function() {
-  assert.equal(calculator.calculate("34 - 12"), 22);
-});
-
-it("добавили умножение: calculate(2 * 3) = 6", function() {
-  calculator.addMethod("*", function(a, b) {
-    return a * b;
+  before(function() {
+    calculator = new Calculator;
   });
-  assert.equal(calculator.calculate("2 * 3"), 6);
-});
 
-it("добавили возведение в степень: calculate(2 ** 3) = 8", function() {
-  calculator.addMethod("**", function(a, b) {
-    return Math.pow(a, b);
+  it("calculate(12 + 34) = 46", function() {
+    assert.equal(calculator.calculate("12 + 34"), 46);
   });
-  assert.equal(calculator.calculate("2 ** 3"), 8);
-});
\ No newline at end of file
+
+  it("calculate(34 - 12) = 22", function() {
+    assert.equal(calculator.calculate("34 - 12"), 22);
+  });
+
+  it("add multiplication: calculate(2 * 3) = 6", function() {
+    calculator.addMethod("*", (a, b) => a * b);
+    assert.equal(calculator.calculate("2 * 3"), 6);
+  });
+
+  it("add power: calculate(2 ** 3) = 8", function() {
+    calculator.addMethod("**", (a, b) => a ** b);
+    assert.equal(calculator.calculate("2 ** 3"), 8);
+  });
+});
diff --git a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/solution.md b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/solution.md
index 3c24691c..41178663 100644
--- a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/solution.md
+++ b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/solution.md
@@ -1,52 +1,3 @@
 
-
-```js run
-function Calculator() {
-
-  var methods = {
-    "-": function(a, b) {
-      return a - b;
-    },
-    "+": function(a, b) {
-      return a + b;
-    }
-  };
-
-  this.calculate = function(str) {
-
-    var split = str.split(' '),
-      a = +split[0],
-      op = split[1],
-      b = +split[2]
-
-    if (!methods[op] || isNaN(a) || isNaN(b)) {
-      return NaN;
-    }
-
-    return methods[op](+a, +b);
-  }
-
-  this.addMethod = function(name, func) {
-    methods[name] = func;
-  };
-}
-
-var calc = new Calculator;
-
-calc.addMethod("*", function(a, b) {
-  return a * b;
-});
-calc.addMethod("/", function(a, b) {
-  return a / b;
-});
-calc.addMethod("**", function(a, b) {
-  return Math.pow(a, b);
-});
-
-var result = calc.calculate("2 ** 3");
-alert( result ); // 8
-```
-
-- Обратите внимание на хранение методов. Они просто добавляются к внутреннему объекту.
-- Все проверки и преобразование к числу производятся в методе `calculate`. В дальнейшем он может быть расширен для поддержки более сложных выражений.
-
+- Please note how methods are stored. They are simply added to the internal object.
+- All tests and numeric conversions are done in the `calculate` method. In future it may be extended to support more complex expressions.
diff --git a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/task.md b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/task.md
index 01be7349..1f6368c0 100644
--- a/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/task.md
+++ b/1-js/04-object-basics/06-constructor-new/4-calculator-extendable/task.md
@@ -2,41 +2,35 @@ importance: 5
 
 ---
 
-# Создайте калькулятор
+# Create an extendable calculator
 
-Напишите конструктор `Calculator`, который создаёт расширяемые объекты-калькуляторы.
+Create a constructor function `Calculator` that creates "extendable" calculator objects.
 
-Эта задача состоит из двух частей, которые можно решать одна за другой.
+The task consists of two parts.
 
-1. Первый шаг задачи: вызов `calculate(str)` принимает строку, например "1 + 2", с жёстко заданным форматом "ЧИСЛО операция ЧИСЛО" (по одному пробелу вокруг операции), и возвращает результат. Понимает плюс `+` и минус `-`.
+1. First, implement the method `calculate(str)` that takes a string like `"1 + 2"` in the format "NUMBER operator NUMBER" (space-delimited) and returns the result. Should understand plus `+` and minus `-`.
 
-    Пример использования:
+    Usage example:
 
     ```js
-    var calc = new Calculator;
+    let calc = new Calculator;
 
     alert( calc.calculate("3 + 7") ); // 10
     ```
-2. Второй шаг -- добавить калькулятору метод `addMethod(name, func)`, который учит калькулятор новой операции. Он получает имя операции `name` и функцию от двух аргументов `func(a,b)`, которая должна её реализовывать.
+2. Then add the method `addOperator(name, func)` that teaches the calculator a new operation. It takes the operator `name` and the two-argument function `func(a,b)` that implements it.
 
-    Например, добавим операции умножить `*`, поделить `/` и возвести в степень `**`:
+    For instance, let's add the multiplication `*`, division `/` and power `**`:
 
     ```js
-    var powerCalc = new Calculator;
-    powerCalc.addMethod("*", function(a, b) {
-      return a * b;
-    });
-    powerCalc.addMethod("/", function(a, b) {
-      return a / b;
-    });
-    powerCalc.addMethod("**", function(a, b) {
-      return Math.pow(a, b);
-    });
+    let powerCalc = new Calculator;
+    powerCalc.addMethod("*", (a, b) => a * b);
+    powerCalc.addMethod("/", (a, b) => a / b);
+    powerCalc.addMethod("**", (a, b) => a ** b);
 
-    var result = powerCalc.calculate("2 ** 3");
+    let result = powerCalc.calculate("2 ** 3");
     alert( result ); // 8
     ```
 
-- Поддержка скобок и сложных математических выражений в этой задаче не требуется.
-- Числа и операции могут состоять из нескольких символов. Между ними ровно один пробел.
-- Предусмотрите обработку ошибок. Какая она должна быть - решите сами.
+- No brackets or complex expressions in this task.
+- The numbers and the operator are delimited with exactly one space.
+- There may be error handling if you'd like to add it.
diff --git a/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/solution.js b/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/solution.js
index b1b50cc5..d15cea2c 100644
--- a/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/solution.js
+++ b/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/solution.js
@@ -1,10 +1,11 @@
 function unique(arr) {
-  var obj = {};
+  let result = [];
 
-  for (var i = 0; i < arr.length; i++) {
-    var str = arr[i];
-    obj[str] = true; // запомнить строку в виде свойства объекта
+  for (let str of arr) {
+    if (!result.includes(str)) {
+      result.push(str);
+    }
   }
 
-  return Object.keys(obj); // или собрать ключи перебором для IE8-
-}
\ No newline at end of file
+  return result;
+}
diff --git a/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/test.js b/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/test.js
index 771317bf..cfc7b1fc 100644
--- a/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/test.js
+++ b/1-js/05-data-types/05-array-methods/11-array-unique/_js.view/test.js
@@ -1,15 +1,15 @@
 describe("unique", function() {
-  it("убирает неуникальные элементы из массива", function() {
-    var strings = ["кришна", "кришна", "харе", "харе",
-      "харе", "харе", "кришна", "кришна", "8-()"
+  it("removes non-unique elements", function() {
+    let strings = ["Hare", "Krishna", "Hare", "Krishna",
+      "Krishna", "Krishna", "Hare", "Hare", ":-O"
     ];
 
-    assert.deepEqual(unique(strings), ["кришна", "харе", "8-()"]);
+    assert.deepEqual(unique(strings), ["Hare", "Krishna", ":-O"]);
   });
 
-  it("не изменяет исходный массив", function() {
-    var strings = ["кришна", "кришна", "харе", "харе"];
+  it("does not change the source array", function() {
+    let strings = ["Krishna", "Krishna", "Hare", "Hare"];
     unique(strings);
-    assert.deepEqual(strings, ["кришна", "кришна", "харе", "харе"]);
+    assert.deepEqual(strings, ["Krishna", "Krishna", "Hare", "Hare"]);
   });
-});
\ No newline at end of file
+});
diff --git a/1-js/05-data-types/05-array-methods/11-array-unique/solution.md b/1-js/05-data-types/05-array-methods/11-array-unique/solution.md
index b34d8daa..9741f531 100644
--- a/1-js/05-data-types/05-array-methods/11-array-unique/solution.md
+++ b/1-js/05-data-types/05-array-methods/11-array-unique/solution.md
@@ -1,78 +1,39 @@
-# Решение перебором (медленное)
-
-Пройдём по массиву вложенным циклом.
-
-Для каждого элемента мы будем искать, был ли такой уже. Если был -- игнорировать:
+Let's walk the array items:
+- For each item we'll check if the resulting array already has that item.
+- If it is so, then ignore, otherwise add to results.
 
 ```js run
 function unique(arr) {
-  var result = [];
+  let result = [];
 
-  nextInput:
-    for (var i = 0; i < arr.length; i++) {
-      var str = arr[i]; // для каждого элемента
-      for (var j = 0; j < result.length; j++) { // ищем, был ли он уже?
-        if (result[j] == str) continue nextInput; // если да, то следующий
-      }
+  for (let str of arr) {
+    if (!result.includes(str) {
       result.push(str);
     }
+  }
 
   return result;
 }
 
-var strings = ["кришна", "кришна", "харе", "харе",
-  "харе", "харе", "кришна", "кришна", "8-()"
+let strings = ["Hare", "Krishna", "Hare", "Krishna",
+  "Krishna", "Krishna", "Hare", "Hare", ":-O"
 ];
 
-alert( unique(strings) ); // кришна, харе, 8-()
+alert( unique(strings) ); // Hare, Krishna, :-O
 ```
 
-Давайте посмотрим, насколько быстро он будет работать.
+The code works, but there's a potential performance problem in it.
 
-Предположим, в массиве `100` элементов. Если все они одинаковые, то `result` будет состоять из одного элемента и вложенный цикл будет выполняться сразу. В этом случае всё хорошо.
+The method `result.includes(str)` internally walks the array `result` and compares each element against `str` to find the match.
 
-А если все, или почти все элементы разные?
+So if there are `100` elements in `result` and no one matches `str`, then it will walk the whole `result` and do exactly `100` comparisons. And if `result` is large, like `10000`, then there would be `10000` comparisons.
 
-В этом случае для каждого элемента понадобится обойти весь текущий массив результатов, после чего -- добавить в этот массив.
+That's not a problem by itself, because Javascript engines are very fast, so walk `10000` array is a matter of microseconds.
 
-1. Для первого элемента -- это обойдётся в `0` операций доступа к элементам `result` (он пока пустой).
-2. Для второго элемента -- это обойдётся в `1` операцию доступа к элементам `result`.
-3. Для третьего элемента -- это обойдётся в `2` операции доступа к элементам `result`.
-4. ...Для n-го элемента -- это обойдётся в `n-1` операций доступа к элементам `result`.
+But we do such test for each element of `arr`, in the `for` loop.
 
-Всего <code>0 + 1 + 2 + ... + n-1 = (n-1)*n/2 = n<sup>2</sup>/2 - n/2</code> (как сумма арифметической прогрессии), то есть количество операций растёт примерно как квадрат от `n`.
+So if `arr.length` is `10000` we'll have something like `10000*10000` = 100 millions of comparisons. That's a lot.
 
-Это очень быстрый рост. Для `100` элементов -- `4950` операций, для `1000` -- `499500` (по формуле выше).
+So the solution is only good for small arrays.
 
-Поэтому такое решение подойдёт только для небольших массивов. Вместо вложенного `for` можно использовать и `arr.indexOf`, ситуация от этого не поменяется, так как `indexOf` тоже ищет перебором.
-
-# Решение с объектом (быстрое)
-
-Наилучшая техника для выбора уникальных строк -- использование вспомогательного объекта `obj`. Ведь название свойства в объекте, с одной стороны -- строка, а с другой -- всегда уникально. Повторная запись в свойство с тем же именем перезапишет его.
-
-Например, если `"харе"` попало в объект один раз (`obj["харе"] = true`), то второе такое же присваивание ничего не изменит.
-
-Решение ниже создаёт объект `obj = {}` и записывает в него все строки как имена свойств. А затем собирает свойства из объекта в массив через `for..in`. Дубликатов уже не будет.
-
-```js run
-function unique(arr) {
-  var obj = {};
-
-  for (var i = 0; i < arr.length; i++) {
-    var str = arr[i];
-*!*
-    obj[str] = true; // запомнить строку в виде свойства объекта
-*/!*
-  }
-
-  return Object.keys(obj); // или собрать ключи перебором для IE8-
-}
-
-var strings = ["кришна", "кришна", "харе", "харе",
-  "харе", "харе", "кришна", "кришна", "8-()"
-];
-
-alert( unique(strings) ); // кришна, харе, 8-()
-```
-
-Так что можно положить все значения как ключи в объект, а потом достать.
\ No newline at end of file
+Further in the chapter <info:map-set-weakmap-weakset> we'll see how to optimize it.
diff --git a/1-js/05-data-types/05-array-methods/11-array-unique/task.md b/1-js/05-data-types/05-array-methods/11-array-unique/task.md
index 24365303..5b56d362 100644
--- a/1-js/05-data-types/05-array-methods/11-array-unique/task.md
+++ b/1-js/05-data-types/05-array-methods/11-array-unique/task.md
@@ -1,24 +1,23 @@
-importance: 3
+importance: 4
 
 ---
 
-# Оставить уникальные элементы массива
+# Filter unique array members
 
-Пусть `arr` -- массив строк.
+Let `arr` be an array.
 
-Напишите функцию `unique(arr)`, которая возвращает массив, содержащий только уникальные элементы `arr`.
+Create a function `unique(arr)` that should return an array with unique items of `arr`.
 
-Например:
+For instance:
 
 ```js
 function unique(arr) {
-  /* ваш код */
+  /* your code */
 }
 
-var strings = ["кришна", "кришна", "харе", "харе",
-  "харе", "харе", "кришна", "кришна", "8-()"
+let strings = ["Hare", "Krishna", "Hare", "Krishna",
+  "Krishna", "Krishna", "Hare", "Hare", ":-O"
 ];
 
-alert( unique(strings) ); // кришна, харе, 8-()
+alert( unique(strings) ); // Hare, Krishna, :-O
 ```
-
diff --git a/1-js/05-data-types/05-array-methods/article.md b/1-js/05-data-types/05-array-methods/article.md
index ab28f7c1..145dd8a2 100644
--- a/1-js/05-data-types/05-array-methods/article.md
+++ b/1-js/05-data-types/05-array-methods/article.md
@@ -535,7 +535,7 @@ The calculation flow:
 
 Or in the form of a table, where each row represents is a function call on the next array element:
 
-|   |`sum`|`current`|результат|
+|   |`sum`|`current`|`result`|
 |---|-----|---------|---------|
 |the first call|`0`|`1`|`1`|
 |the second call|`1`|`2`|`3`|
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/_js.view/solution.js b/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/_js.view/solution.js
new file mode 100644
index 00000000..de504e1e
--- /dev/null
+++ b/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/_js.view/solution.js
@@ -0,0 +1,3 @@
+function unique(arr) {
+  return Array.from(new Set(arr));
+}
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/_js.view/test.js b/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/_js.view/test.js
new file mode 100644
index 00000000..cfc7b1fc
--- /dev/null
+++ b/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/_js.view/test.js
@@ -0,0 +1,15 @@
+describe("unique", function() {
+  it("removes non-unique elements", function() {
+    let strings = ["Hare", "Krishna", "Hare", "Krishna",
+      "Krishna", "Krishna", "Hare", "Hare", ":-O"
+    ];
+
+    assert.deepEqual(unique(strings), ["Hare", "Krishna", ":-O"]);
+  });
+
+  it("does not change the source array", function() {
+    let strings = ["Krishna", "Krishna", "Hare", "Hare"];
+    unique(strings);
+    assert.deepEqual(strings, ["Krishna", "Krishna", "Hare", "Hare"]);
+  });
+});
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/solution.md b/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/solution.md
new file mode 100644
index 00000000..e69de29b
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/task.md b/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/task.md
new file mode 100644
index 00000000..d6803003
--- /dev/null
+++ b/1-js/05-data-types/07-map-set-weakmap-weakset/01-array-unique-map/task.md
@@ -0,0 +1,27 @@
+importance: 5
+
+---
+
+# Filter unique array members
+
+Let `arr` be an array.
+
+Create a function `unique(arr)` that should return an array with unique items of `arr`.
+
+For instance:
+
+```js
+function unique(arr) {
+  /* your code */
+}
+
+let values = ["Hare", "Krishna", "Hare", "Krishna",
+  "Krishna", "Krishna", "Hare", "Hare", ":-O"
+];
+
+alert( unique(values) ); // Hare, Krishna, :-O
+```
+
+P.S. Here strings are used, but can be values of any type.
+
+P.P.S. Use `Set` to store unique values.
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/_js.view/solution.js b/1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/_js.view/solution.js
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/_js.view/solution.js
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/_js.view/solution.js
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/_js.view/test.js b/1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/_js.view/test.js
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/_js.view/test.js
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/_js.view/test.js
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/solution.md b/1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/solution.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/solution.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/solution.md
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/task.md b/1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/task.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/01-filter-anagrams/task.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/02-filter-anagrams/task.md
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/02-iterable-keys/solution.md b/1-js/05-data-types/07-map-set-weakmap-weakset/03-iterable-keys/solution.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/02-iterable-keys/solution.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/03-iterable-keys/solution.md
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/02-iterable-keys/task.md b/1-js/05-data-types/07-map-set-weakmap-weakset/03-iterable-keys/task.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/02-iterable-keys/task.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/03-iterable-keys/task.md
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/03-recipients-read/solution.md b/1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-read/solution.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/03-recipients-read/solution.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-read/solution.md
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/03-recipients-read/task.md b/1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-read/task.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/03-recipients-read/task.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-read/task.md
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-when-read/solution.md b/1-js/05-data-types/07-map-set-weakmap-weakset/05-recipients-when-read/solution.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-when-read/solution.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/05-recipients-when-read/solution.md
diff --git a/1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-when-read/task.md b/1-js/05-data-types/07-map-set-weakmap-weakset/05-recipients-when-read/task.md
similarity index 100%
rename from 1-js/05-data-types/07-map-set-weakmap-weakset/04-recipients-when-read/task.md
rename to 1-js/05-data-types/07-map-set-weakmap-weakset/05-recipients-when-read/task.md
diff --git a/1-js/05-data-types/09-destructuring-assignment/article.md b/1-js/05-data-types/09-destructuring-assignment/article.md
index d043351d..864eb3d8 100644
--- a/1-js/05-data-types/09-destructuring-assignment/article.md
+++ b/1-js/05-data-types/09-destructuring-assignment/article.md
@@ -251,7 +251,7 @@ let options = {
 let {width=100, height=200, title} = options;
 */!*
 
-alert(title);  // Меню
+alert(title);  // Menu
 alert(width);  // 100
 alert(height); // 200
 ```
diff --git a/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/source.js b/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/source.js
index 26e19c75..74989df2 100644
--- a/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/source.js
+++ b/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/source.js
@@ -1,4 +1,6 @@
 
+let arr = [1, 2, 3, 4, 5, 6, 7];
+
 function inBetween(a, b) {
   // ...your code...
 }
diff --git a/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/test.js b/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/test.js
index 5dd5d027..86d2d3b4 100644
--- a/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/test.js
+++ b/1-js/06-more-functions/03-closure/6-filter-through-function/_js.view/test.js
@@ -19,4 +19,3 @@ describe("inBetween", function() {
     assert.isFalse(filter(0));
   });
 });
-
diff --git a/1-js/06-more-functions/03-closure/6-filter-through-function/solution.md b/1-js/06-more-functions/03-closure/6-filter-through-function/solution.md
index b9657971..5bbc33b0 100644
--- a/1-js/06-more-functions/03-closure/6-filter-through-function/solution.md
+++ b/1-js/06-more-functions/03-closure/6-filter-through-function/solution.md
@@ -1,79 +1,26 @@
-# Функция фильтрации
+
+# Filter inBetween
 
 ```js run
-function filter(arr, func) {
-  var result = [];
-
-  for (var i = 0; i < arr.length; i++) {
-    var val = arr[i];
-    if (func(val)) {
-      result.push(val);
-    }
-  }
-
-  return result;
-}
-
-var arr = [1, 2, 3, 4, 5, 6, 7];
-
-alert(filter(arr, function(a) {
-  return a % 2 == 0;
-})); // 2, 4, 6
-```
-
-# Фильтр inBetween
-
-```js run
-function filter(arr, func) {
-  var result = [];
-
-  for (var i = 0; i < arr.length; i++) {
-    var val = arr[i];
-    if (func(val)) {
-      result.push(val);
-    }
-  }
-
-  return result;
-}
-
-*!*
 function inBetween(a, b) {
-    return function(x) {
-      return x >= a && x <= b;
-    };
-  }
-*/!*
-
-var arr = [1, 2, 3, 4, 5, 6, 7];
-alert( filter(arr, inBetween(3, 6)) ); // 3,4,5,6
-```
-
-# Фильтр inArray
-
-```js run
-function filter(arr, func) {
-  var result = [];
-
-  for (var i = 0; i < arr.length; i++) {
-    var val = arr[i];
-    if (func(val)) {
-      result.push(val);
-    }
-  }
-
-  return result;
+  return function(x) {
+    return x >= a && x <= b;
+  };
 }
 
-*!*
-function inArray(arr) {
-    return function(x) {
-      return arr.indexOf(x) != -1;
-    };
-  }
-*/!*
-
-var arr = [1, 2, 3, 4, 5, 6, 7];
-alert( filter(arr, inArray([1, 2, 10])) ); // 1,2
+let arr = [1, 2, 3, 4, 5, 6, 7];
+alert( arr.filter(inBetween(3, 6)) ); // 3,4,5,6
 ```
 
+# Filter inArray
+
+```js run
+function inArray(arr) {
+  return function(x) {
+    return arr.includes(x);
+  };
+}
+
+let arr = [1, 2, 3, 4, 5, 6, 7];
+alert( arr.filter(inArray([1, 2, 10])) ); // 1,2
+```
diff --git a/1-js/06-more-functions/03-closure/7-sort-by-field/task.md b/1-js/06-more-functions/03-closure/7-sort-by-field/task.md
index 181fa6ff..7e7690da 100644
--- a/1-js/06-more-functions/03-closure/7-sort-by-field/task.md
+++ b/1-js/06-more-functions/03-closure/7-sort-by-field/task.md
@@ -8,7 +8,7 @@ We've got an array of objects to sort:
 
 ```js
 let users = [
-  { name: "John", age: 20, surname: "Johnson" }, 
+  { name: "John", age: 20, surname: "Johnson" },
   { name: "Pete", age: 18, surname: "Peterson" },
   { name: "Ann", age: 19, surname: "Hathaway" }
 ];
@@ -20,7 +20,7 @@ The usual way to do that would be:
 // by name (Ann, John, Pete)
 users.sort((a, b) => a.name > b.name ? 1 : -1);
 
-// по age (Pete, Ann, John)
+// by age (Pete, Ann, John)
 users.sort((a, b) => a.age > b.age ? 1 : -1);
 ```
 
@@ -33,4 +33,4 @@ users.sort(byField('age'));
 
 So, instead of writing a function, just put `byField(fieldName)`.
 
-Write the function `byField` that can be used for that.
\ No newline at end of file
+Write the function `byField` that can be used for that.
diff --git a/1-js/06-more-functions/03-closure/8-make-army/_js.view/solution.js b/1-js/06-more-functions/03-closure/8-make-army/_js.view/solution.js
index 2455c301..a26578ae 100644
--- a/1-js/06-more-functions/03-closure/8-make-army/_js.view/solution.js
+++ b/1-js/06-more-functions/03-closure/8-make-army/_js.view/solution.js
@@ -1,19 +1,13 @@
 function makeArmy() {
 
-  var shooters = [];
-
-  for (var i = 0; i < 10; i++) {
-
-    var shooter = (function(x) {
-
-      return function() {
-        alert(x);
-      };
-
-    })(i);
+  let shooters = [];
 
+  for(let i = 0; i < 10; i++) {
+    let shooter = function() { // shooter function
+      alert( i ); // should show its number
+    };
     shooters.push(shooter);
   }
 
   return shooters;
-}
\ No newline at end of file
+}
diff --git a/1-js/06-more-functions/03-closure/8-make-army/_js.view/source.js b/1-js/06-more-functions/03-closure/8-make-army/_js.view/source.js
index f9058674..7c7aaa1e 100644
--- a/1-js/06-more-functions/03-closure/8-make-army/_js.view/source.js
+++ b/1-js/06-more-functions/03-closure/8-make-army/_js.view/source.js
@@ -1,13 +1,22 @@
 function makeArmy() {
+  let shooters = [];
 
-  var shooters = [];
-
-  for (var i = 0; i < 10; i++) {
-    var shooter = function() { // функция-стрелок
-      alert(i); // выводит свой номер
+  let i = 0;
+  while (i < 10) {
+    let shooter = function() { // shooter function
+      alert( i ); // should show its number
     };
     shooters.push(shooter);
+    i++;
   }
 
   return shooters;
-}
\ No newline at end of file
+}
+
+/*
+let army = makeArmy();
+
+army[0](); // the shooter number 0 shows 10
+army[5](); // and number 5 also outputs 10...
+// ... all shooters show 10 instead of their 0, 1, 2, 3...
+*/
diff --git a/1-js/06-more-functions/03-closure/8-make-army/_js.view/test.js b/1-js/06-more-functions/03-closure/8-make-army/_js.view/test.js
index fdfabf66..b61e6e4d 100644
--- a/1-js/06-more-functions/03-closure/8-make-army/_js.view/test.js
+++ b/1-js/06-more-functions/03-closure/8-make-army/_js.view/test.js
@@ -1,20 +1,25 @@
-var army;
-before(function() {
-  army = makeArmy();
-  window.alert = sinon.stub(window, "alert");
+describe("army", function() {
+
+  let army;
+  
+  before(function() {
+    army = makeArmy();
+    window.alert = sinon.stub(window, "alert");
+  });
+
+  it("army[0] shows 0", function() {
+    army[0]();
+    assert(alert.calledWith(0));
+  });
+
+
+  it("army[5] shows 5", function() {
+    army[5]();
+    assert(alert.calledWith(5));
+  });
+
+  after(function() {
+    window.alert.restore();
+  });
+
 });
-
-it("army[0] выводит 0", function() {
-  army[0]();
-  assert(alert.calledWith(0));
-});
-
-
-it("army[5] функция выводит 5", function() {
-  army[5]();
-  assert(alert.calledWith(5));
-});
-
-after(function() {
-  window.alert.restore();
-});
\ No newline at end of file
diff --git a/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy.png b/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy.png
index 72266fca..d51e8167 100644
Binary files a/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy.png and b/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy.png differ
diff --git a/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy@2x.png b/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy@2x.png
index c9dd8817..e70edbd6 100644
Binary files a/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy@2x.png and b/1-js/06-more-functions/03-closure/8-make-army/lexenv-makearmy@2x.png differ
diff --git a/1-js/06-more-functions/03-closure/8-make-army/solution.md b/1-js/06-more-functions/03-closure/8-make-army/solution.md
index cbd4e56f..03c34b07 100644
--- a/1-js/06-more-functions/03-closure/8-make-army/solution.md
+++ b/1-js/06-more-functions/03-closure/8-make-army/solution.md
@@ -1,12 +1,12 @@
 
-The function `makeArmy` does the following:
+Let's examine what's done inside `makeArmy`, and the solution will become obvious.
 
-1. Creates an empty array `shooters`:
+1. It creates an empty array `shooters`:
 
     ```js
     let shooters = [];
     ```
-2. Fills it in the loop via `shooters.push`.
+2. Fills it in the loop via `shooters.push(function...)`.
 
     Every element is a function, so the resulting array looks like this:
 
@@ -27,15 +27,31 @@ The function `makeArmy` does the following:
 
 3. The array is returned from the function.
 
-The call to `army[5]()` -- is getting the element `army[5]` from the array (it will be a function) and -- the immediate call of it.
+Then, later, the call to `army[5]()` will get the element `army[5]` from the array (it will be a function) and call it.
 
-Now why all shooters show the same.
+Now why all such functions show the same?
 
-There's no local variable `i` inside `shooter` functions. When such a function is called, it takes `i` from its outer lexical environment.
+That's because there's no local variable `i` inside `shooter` functions. When such a function is called, it takes `i` from its outer lexical environment.
 
 What will be the value of `i`?
 
-It lives in the lexical environment associated with `makeArmy()` run. At the moment of the call, `makeArmy` already finished its job. The last value of `i` in the `while` loop was `i=10`.
+If we look at the source:
+
+```js
+function makeArmy() {
+  ...
+  let i = 0;
+  while (i < 10) {
+    let shooter = function() { // shooter function
+      alert( i ); // should show its number
+    };
+    ...
+  }
+  ...
+}
+```
+
+...We can see that it lives in the lexical environment associated with the current `makeArmy()` run. But when `army[5]()` is called, `makeArmy` has already finished its job, and `i` has the last value: `10` (the end of `while`).
 
 As a result, all `shooter` functions get from the outer lexical envrironment the same, last value `i=10`.
 
@@ -43,7 +59,7 @@ The fix can be very simple:
 
 ```js run
 function makeArmy() {
-  
+
   let shooters = [];
 
 *!*
@@ -70,7 +86,9 @@ So, the value of `i` now lives a little bit closer. Not in `makeArmy()` Lexical
 
 ![](lexenv-makearmy.png)
 
-Here we rewrote `while` into `for`. But it is also possible to keep the existing `while` structure:
+Here we rewrote `while` into `for`.
+
+Another trick could be possible, let's see it for better understanding of the subject:
 
 
 ```js run
@@ -98,7 +116,6 @@ army[0](); // 0
 army[5](); // 5
 ```
 
-Look at the trick. The `while` loop, just like `for`, makes a new Lexical Environment for each run. So we must make sure that it gets the right value for a `shooter` will access it.
+The `while` loop, just like `for`, makes a new Lexical Environment for each run. So here we make sure that it gets the right value for a `shooter`.
 
 We copy `let j = i`. This makes a loop body local `j` and copies the value of `i` to it. Primitives are copied "by value", so we actually get a complete independent copy of `i`, belonging to the current loop iteration.
-
diff --git a/1-js/06-more-functions/07-settimeout-setinterval/article.md b/1-js/06-more-functions/07-settimeout-setinterval/article.md
index 3f977fb0..63f8f5bf 100644
--- a/1-js/06-more-functions/07-settimeout-setinterval/article.md
+++ b/1-js/06-more-functions/07-settimeout-setinterval/article.md
@@ -37,7 +37,7 @@ For instance, this code calls `sayHi()` after one second:
 
 ```js run
 function sayHi() {
-  alert( 'Привет' );
+  alert('Hello');
 }
 
 *!*
@@ -353,7 +353,7 @@ For server-side Javascript, that limitation does not exist. Also, there are othe
 
 ## Summary
 
-- Methods `setInterval(func, delay, ...args)` и `setTimeout(func, delay, ...args)` allow to run the `func` regularly/once after `delay` milliseconds.
+- Methods `setInterval(func, delay, ...args)` and `setTimeout(func, delay, ...args)` allow to run the `func` regularly/once after `delay` milliseconds.
 - To cancel execution, we should `clearInterval/clearTimeout` on the value returned by `setInterval/setTimeout`.
 - Nested `setTimeout` calls give more flexible control over the execution than `setInterval`. They also can guarantee the minimal time *between* the execution.
 - Zero-timeout is sometimes used to schedule the call "as soon as possible".
diff --git a/1-js/06-more-functions/10-arrow-functions/article.md b/1-js/06-more-functions/10-arrow-functions/article.md
index e2e71b38..7987925c 100644
--- a/1-js/06-more-functions/10-arrow-functions/article.md
+++ b/1-js/06-more-functions/10-arrow-functions/article.md
@@ -103,8 +103,6 @@ sayHiDeferred("John"); // Hello, John after 2 seconds
 
 The same without an arrow function would look like:
 
-Аналогичная реализация без функции-стрелки выглядела бы так:
-
 ```js
 function defer(f, ms) {
   return function(...args) {
diff --git a/figures.sketch b/figures.sketch
index 222b10a7..95586868 100644
Binary files a/figures.sketch and b/figures.sketch differ