【正文】
introduced D. had been introduced18. Where do you think ______ he ______ the puter? Sorry. I have no idea. A. has。 bought C. did。 buys19. Don’t bother to look for my dictionary it ______ some day. A. turns up B. has turned up C. will turn up D. is going to turn up20. What do you think of this kind of TV set, which ______ in Shanghai? Well, I don’t care about such things. A. was made B. is made C. has been made D. had been made21. Did he notice you enter the room? I don’t think so. He ______ to the radio with his eyes shut. A. listened B. was listening C. has listened D. had listened22. The plane ______ at 7:00 pm, so I have to be at the airport by 6:40 at the latest. A. has left B. would leave C. will have left D. leaves23. The train ___ at the present speed until it reaches the foot of the mountain at about nine o’clock tonight. A. went B. is going C. goes D. will be going24. I used to drink a lot of tea but these days I ______ coffee. A. prefer B. preferred C. had preferred D. am preferring25. The vegetables didn’t taste very good. They ______ too long. A. had been cooked B. were cooked C. have cooked D. cooked26. Remember the first time we met, Jim? Of course I do. You ______ in the library. A. were reading B. had read C. have read D. read27. I want to buy that kind of cloth because I ______ the cloth ______ well.A. have told。 washesC. was told。 is washed28. Is Tom still smoking? No. By next Saturday he ______ for a whole month without smoking a single cigarette. A. will be B. will have goneC. will have been D. has been going29. ______ Betty this morning? Not yet, but she is sure to be here b