38. —_______ the bulb yet?  —Yes, I _________ it a few minutes ago.

A. Do you change, changed         B. Did you changed, have changed

C. Have you changed, changed      D. Have you changed, have change

39. —Do you think sixteen-year-olds ______ drive?

—I don’t think so. They are too young. They aren’t serious enough.

A. should allow to          B. should not be allowed to

C. should not allow to       D. should be allowed to

40. Our teacher often tells us ____ the windows before we leave.

A. close     B. closed      C. to close     D. closing

41. I like singers _________ sing the words clearly.

A. which     B. when      C. who        D. what

42. The boss made him ______ for twelve hours a day.

A. work         B. worked     C. to work     D. works

43. —Do you know Wal-Mart?

—Yes. It’s the best shopping center _______ I know in this city.

A. where      B. which        C. in which     D. that

44. We’ll go hiking ________ it rains tomorrow.

A. if       B. because       C. since      D. unless

45. ---Whose book is this?  --- It must belong to_____.

A. I         B. Diana’s      C. Diana     D. my