题目内容：

Find the only one mistake in each line and correct it.

Today we want to tell you something about studying a language,

English in particular. Students learned a language by learn           21.1.

grammar rules and word lists in the past. Some unlucky ones

still use this way. You can’t become skillful in speaking a language

if you don’t use it. And all modern ways is based on this theory.      22.2.

The course called “Look, Listen and Learn!” can help you.

English is the official language using in so many countries.       23. 3.

And it has also become international and is second language         24. 4.

in most of the countries. Perhaps through English we

will be able to understand each other more better. We will be         25. 5.

able to communicate with anyone all around the world.