44. Charles Babb age is generally considered ____ the first computer.

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

43. The computer center, ___ last year, is very popular among the students in the school.

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

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

A. angrily pointing　　 B. and point angrily　 C. angrily pointed　 D. and angrily pointing

41. ---- I thought you had planed to practise the piano today.

　 ---- I did nothing but _____ letters all day.

A. write　 B. to write　 C. wrote　 D. writing

40. I would appreciate ____ back this afternoon..

A. you to call　 B. you call　 C. your calling　 D. you’re calling

39. --- I usually go there by train.

　 --- Why not ___ by boat for a change?

A. to try going　 B. trying to go　 C. to try and go　 D. try going

38. ---- Have you decide when ____?

　 ---- Yes, tomorrow morning.

A. to leave　 B. to be leaving　 C. will you leave　 D. are you leaving

37. The salesman scolded the girl caught ___ and let her off.

A. to have stolen　 B. to be stealing　 C. to steal　 D. stealing

36. ______ a reply, he decided to write again.

A. not receiving　　 B. receiving not　 C. not having received　 D. having not received

35. I can hardly imagine peter ____ across the Atlantic Ocean in five days.

　A. sail　 B. to sail　 C. sailing　 D. to have sailed