minor

1-js/02-first-steps/04-variables/article.md

@@ -221,14 +221,13 @@ alert(num); // 5
 
 That's a bad practice, it gives an error in the strict mode:
 
-```js run untrusted
+```js run refresh untrusted
 "use strict";
 
 *!*
 num = 5; // error: num is not defined
 */!*
 ```
-
 ````
 
 ## Constants