从A、B、C、D四个选项中，选出与所给句子画线部分意义相同或相近并能代替的那一项。

1. —May I  use your bike? I left my English book at home. I have to go and get it.

    —Sure. Here's the key.

A. keep

B. borrow

C. get

D. lend

2. —Could you help me take these new books to the classroom? 

   —OK. I'll do it right now.

A. at that moment

B. at the moment

C. in a moment

D. a moment ago

3. Not all teachers agree that spending too much time on the Internet is good for students.

A. Lots of

B. Few

C. Many

D. Some

4. —Shall we meet at a quarter to eight?

    —That's too early. Let's make it half past eight.

A. come at

B. goat

C. meet at

D. leave at

5. —I like to eat fish and chips in the open air. What about you?

    —Me, too.

A. So do I.

B. So am I.

C. Either is OK.

D. You decide.

燃烧过程中的氧化剂主要是氧。空气中氧的含量大约为()。

（A）14%

（B）21%

（C）78%

（D）87%