29. Paul doesn’t have to be made ____ . He always works hard .

　　 A . learn　　 B . to learn　　 C . learned　　 D . learning

28. The first textbooks ____ for teaching English as a foreign language came out in the 16th century .

　　 A . having written　　 B . to be written　　 C . being written　　 D . written

27. The visiting minister expressed his satisfaction with the talks , ____ that he had enjoyed his stay here .

　　 A . having added　　 B . to add　　 C . adding　　 D . added

26. The missing boys were last seen ____ near the river .

　　 A . playing　　 B . to be playing　　 C . play　　 D . to play

25. Rather than ____ on a crowded bus , he always prefers ____ a bicycle .

　　 A . ride ; ride　　 B . riding ; ride　　 C . ride ; to ride　　 D . to ride ; riding

24.- I must apologize for ____ ahead of time .

　　　 - That‘s all right .

　　 A . letting you not know　　 B . not letting you know

　　 C . letting you know not　　 D . letting not you know

23. Charles Babbage is generally considered ____ the first computer .

　　 A . to invent　　 B . inventing　　 C . to have invented　　 D . having invented

22. The computer centre , ____ last year , is very popular among the students in this school .

　　 A . open　　 B . opening　　 C . having opened　　 D . opened

21. 　　　　　　more attention , the trees could have grown better .

　　 A. Given　　　　　　　　 B. To give C. Giving　　　　　　 D. Having given

20. “Can’t you read ? ”Mary said ____ to the notice .

　　 A . angrily pointing　　 B . and point angrily

　　 C . angrily pointed　　 D . and angrily pointing