29.If you are an athlete, strong abdominal muscles help you ensure a strong back and freedom from injury during（ ）upper-body movement.

51.——“What courses are you going to do next semester?”——“I don’t know. But it’s about time（ ）on something.”

50.（ ）for the fact that she broke her leg, she might have passed the exam.

49.The experiment requires more money than（ ）.

48.Fool（ ）Jane is, she could not have done such a thing.

47.She managed to save（ ）she could out of her wages to help her brother.

46.AIDS is said（ ）the number-one killer of both men and women over the past few years in that region.

45.We’ve just installed two air-conditioners in our apartment,（ ）should make great differences in our life next summer.

44.Have you ever been in a situation（ ）you know the other person is right yet you cannot agree with him?

43.For some time now, world leaders（ ）out the necessity for agreement on arms reduction.

42.（ ）of the twins was arrested, because I saw both at a party last night.