21. "Hurry up! We're waiting for you. What's taking you so long?" "I________ for an important phone call. Go ahead and leave without me." A. Wait B. will wait C. am waiting D. have waited 22. Robert is going to be famous some day. He_________in three movies already. ~ I'm sure he'll be a star. A. Has been appearing B. had appeared C. has appeared D. appeared 23. Where's Polly? ~She_________. A. Is in her room studying B. in her room is studying C. studies in her room D. has in her room studied 24. Hello? Alice? This is Jeff. How are you? ~ Jeff? What a coincidence! I_________ about you when the phone rang. A. Was just thinking B. just thought C. have just been thinking D. was just thought 25. What___________ about the new simplified tax? ~It's more confusing than the old one. A. Are you thinking B. do you think C. have you thought D. have you been thinking 26. When is Mr. Fields planning to retire? ~ Soon, I think. He________ here for a long time. He'll probably retire next year or the year after that. A. Worked B. had been working C. has been working D. is working 27. Why did you buy all this sugar and chocolate? ~ I_________a delicious dessert for dinner tonight. A. Make B. will make C. am going to make D. will have made 28. Let's go! What's taking you so long? ~ I'll be there as soon as I__________my keys. A. Found B. will find C. find D. am finding 29. Next week when there______ a full moon, the ocean tides sill be higher. A. Is being B. is C. will be D. will have been 30. While I______TV last night, a mouse ran across the floor. A. Watch B. watched C. was watching D. am watching 31. Fish were among the earliest forms of life. Fish__________ on earth for ages and ages. A. Existed B. are existing C. exist D. have existed 32. The phone ________constantly since Jack announced his candidacy for president this morning. A. Has been ringing B. rang C. had rung D. had been ringing 33. The earth_________on the sun for its heat and light. A. Is depend B. depending C. has depended D. depends 34. I don't feel good. I________ home from work tomorrow. A. Am staying B. stay C. will have stayed D. stayed 35. Today there are weather satellites that beam down information about the earth's atmosphere. In the last two decades, space exploration_________ great contributions to weather forecasting. A. Is making B. has made C. made D. makes