在H、He、C、N、Al五种元素中，选择适当元素组成符合下列要求的物质（写化学式）：

（1）可用于填充探空气球和作焊接金属保护气的物质是______．

（2）可用作燃料的化合物是______（写出一种即可）．

（3）由在地壳中含量占第一位的元素和上述五种元素中的金属元素形成的化合物是______．

单词拼写。

1. I like ______ (跳舞) and playing the guitar.

2. _____  (唱歌) is her favourite.

3. She is Chinese, but she _____ (说) English very well.

4. The ______ (年轻人) like guitars and sports.

5. He wants to be a ______(音乐家) in the future (将来).

6. What's your e-mail _______ (地址)?

7. Can you ______ (表演) us how to play the guitar?

8. She says she likes _______ (画画).

9. He _____ (参加) the art club in the evening.

10. Do you want to go to the _______ (象棋) club.