Fix typos in 4.3 (Blob)

4-binary/03-blob/article.md

@@ -55,7 +55,7 @@ This behavior is similar to JavaScript strings: we can't change a character in a
 
 ## Blob as URL
 
-A Blob can be easily used as an URL for `<a>`, `<img>` or other tags, to show its contents.
+A Blob can be easily used as a URL for `<a>`, `<img>` or other tags, to show its contents.
 
 Thanks to `type`, we can also download/upload `Blob` objects, and the `type` naturally becomes `Content-Type` in network requests.
 
@@ -99,7 +99,7 @@ blob:https://javascript.info/1e67e00e-860d-40a5-89ae-6ab0cbee6273
 
 For each URL generated by `URL.createObjectURL` the browser stores a URL -> `Blob` mapping internally. So such URLs are short, but allow to access the `Blob`.
 
-A generated URL (and hence the link with it) is only valid within the current document, while it's open. And it allows to reference the `Blob` in `<img>`, `<a>`, basically any other object that expects an url.
+A generated URL (and hence the link with it) is only valid within the current document, while it's open. And it allows to reference the `Blob` in `<img>`, `<a>`, basically any other object that expects a URL.
 
 There's a side-effect though. While there's a mapping for a `Blob`, the `Blob` itself resides in the memory. The browser can't free it.
 
@@ -151,7 +151,7 @@ reader.onload = function() {
 };
 ```
 
-Both ways of making an URL of a `Blob` are usable. But usually `URL.createObjectURL(blob)` is simpler and faster.
+Both ways of making a URL of a `Blob` are usable. But usually `URL.createObjectURL(blob)` is simpler and faster.
 
 ```compare title-plus="URL.createObjectURL(blob)" title-minus="Blob to data url"
 + We need to revoke them if care about memory.