14. He 　　　　　(write)since 8 o'clock this morning.

答案:has been writing

15. I'm very tired. I 　　　　　(play)football.

答案:have been playing

16. His books 　　　　　(become)very popular with teenagers since the end of 1990s. Many students 　　　　　(write)to him after reading them.

答案:have become;wrote

17. No one knew when the fire 　　　　　(break out), but they knew it　　　(put out)the next morning.

答案:broke out;was put out

18. I have no idea what 　　　　　(happen)while I was asleep.

答案:happened

19. Great changes 　　　　　(take place)in the past ten years.

答案:have taken place

20. It's the third time that I 　　　　　(be)to Hong Kong.

答案:have been

三、阅读理解

　　A little stream ran down from a high mountain through many villages and forests. Then it reached a desert. "I went through so many difficulties. I should have no problem crossing the desert, " she thought. As she started, she found herself slowly disappearing into the sand. After many tries, she still failed. "Maybe I can't reach the ocean", she said sadly to herself.

　　At this time, a deep voice said, "If a breeze (微风)can cross the desert, so can a river. " It was the voice of the desert. But the little stream answered, "That's because a breeze can fly, but I cannot. "

"That's because you can't give up what you are. Let yourself evaporate (蒸汽)into the breeze, and it can take you across the desert. " said the desert. "Give up what I am now?No!No!" The little stream could not accept this idea. "The breeze can carry the vapor (蒸汽)across the desert and let it leave as rain. The rain will form a river again, " said the desert. "And whether you're a