13．Scientists often make 　________ (实验)on animals．

12．Jack ________ (描述)the robbery in detail．

11．He takes an ________ (积极的)part in politics．

10．One of the most ________ (danger)animals in the world is the giant panda．

C．根据句意和所给汉语意思，用英语完成句子。(5分)

9．I couldn’t fall asleep because some children were playing ________ (noise)down stairs．

8．The boy doesn’t do well in his lessons because he is too ________ (play．)

7．Not ________ (know)English，I couldn’t understand what he was talking about．

6．He learned how to swim without ________ (teach)．

5．His s________ researches are very important．

B．根据句意，用所给单词的适当形式填空。(5分)　　 。

4．Last Sunday we had a p__________ time．