根据首字母或汉语提示填入适当的词。

1. He can't speak in front of people. He is s_____.

2. I'll study hard. I don't want to let my parents d_____.

3. He is _____ (自信的) to pass the exam.

4. Without my _____ (允许), don't touch my things.

5. I am very busy. Don't b_____ me, OK?

6. The population of the world i_____ very fast.

7. He is _____ (精力充沛的). He can do everything well enough.

8. Do you know the h_____ of the basketball?