35.The scientists are trying to find out the facts to（ ）their theory.

90.The gray building is where the workers live, and the white one is where the spare parts（ ）.

89.I suppose that when I come back in ten years’ time all those old houses（ ）down.

88.I decided to go to the library as soon as I（ ）.

87.Ever since the family moved to the suburbs last year, they（ ）better health.

86.I’m awfully sorry, but I had no alternative. I simply（ ）what I did.

85.In recent years many football clubs（ ）as business to make a profit.

84.The crazy fans（）patiently for two hours and they would wait till the movie star arrived.

83.The new staff resigned last Monday after（ ）to work overtime.

82.When we receive the goods you return to us, you（ ）a full refund with a week.

81.While nuclear weapons present grave（ ）dangers, the predominant crisis of overpopulation is with us today.