解析　play a trick on为固定短语，意为"搞恶作剧，开玩笑"；have fun意为"玩得开心"，fun是不可数名词，前面通常不加冠词。

17. Don't be discouraged.________things as they are and you will enjoy every day of your life.

A.Taking B.To take

C.Take D.Taken

答案　C

解析　考查"祈使句＋and＋简单句"句型。表示"如果......就......"。答案选C。

18.-What do you think of the sudden news?

-Well，it is quite________and I am quite________at it.

A.amazed；amazed B.amazing；amazing

C.amazing；amazed D.amazed；amazing

答案　C

解析　句意：--你怎样认为这突如其来的消息？--呵，这消息太令人吃惊了，我感到很吃惊。amazed感到吃惊的；amazing令人吃惊的。

19.Remember that it will make a good________on others if you are very polite to everyone there.

A.decision B.situation

C.impression D.position

答案　C