4. I have always written with my left hand.

3. This dinner was the most expensive meal we have ever had.

2. Have you ever seen a UFO?

1 我已经看了说明，但我还是不理解。

2 你看见过不明飞行物吗？

3 这是我们吃过的最贵的一顿饭。

4 我一直用左手写字。

5 在过去的二十年里我们国家发生了巨大的变化。

6 迄今为止你读了多少英文小说？

7 他家搬到澳大利亚已经八年了。

8 他父亲去世后，他就一直和他的叔叔住在一起。

Keys:

20. I won’t tell the student the answer to the math problem until he ____ on it for more than an hour. (2006湖北)

A. has been working　　 B. will have worked　　 C. will have been working　　 D. had worked

19. Although medical science ____ control over several dangerous diseases, what worries us is that some of them are returning. (2006江苏)

　 A. achieved　　　　　 B. has achieved　　 C. will achieve　　　　　 D. had achieved

18. I ____ in London for many years, but I’ve never regretted my final decision to move back to China. (2006重庆)

　A. lived　　　 B. was living　　 C. have lived　　 D. had lived

17. My brother is an actor. He _________ in several films so far. (2005浙江卷)

　　　 A．appears　　 B．appeared C．has appeared　　　 D．is appearing

16. The coffee is wonderful ! It doesn’t taste like anything I _____ before. (2005全国卷I)

　　　 A．was having 　　 B．have 　　　 C．have ever had D．had ever had

14. --The window is dirty. --I know. It ________ for weeks. (2004广西高考)

　　 A. hasn’t cleaned　　 B. didn’t clean　 C. wasn’t cleaned　 D. hasn’t been cleaned

15 Years ago we didn't know this, but recent science ______ that people who don't sleep well soon get ill. (2005广东高考)

A. showed　　　　 　　　B. has shown　　　　 C. will show　　　　 D. is showing