根据句意，用括号中所给词的正确形式填空。

1. He is very young but he looks _____ (health).

2.－When did he _____the game _____ (design)?

   －In 2005.

3. Nothing in the world is _____ (possible) if you put your heart into it.

4. We are told _____ (not laugh) at the people in trouble.

5. No matter where we are, We should do something _____ (use).

6. One word can have several _____ (mean).

7. Half a century _____ (pass) since he came to China.

关于多西环素的叙述错误的是（）

A.是半合成的长效四环素类抗生素

B.与四环素的抗菌谱相似

C.抗菌活性比四环素强

D.口服吸收量少且不规则

E.可用于前列腺炎的治疗