1. George applied for the position three times _____ he finally got it.

A. before B. until C. when D. after

2. This robot is supposed to save a lot of labor, but it remains a problem if it _____.

A. is B. saves C. does D. has

3. There were many more people who got injured in the big fire than _____.

A. was reported B. it was reported

C. were reported D. they were reported

參考答案及解析：

1. A。強(qiáng)調(diào)從句中謂語動詞的動作發(fā)生的晚，表示“……才……”。故答案為A。

2. C。does 是代動詞，用來代替上文save a lot of labor。故答案為C。

3. A。比較狀語從句中省略與主句相同的成分，只保留比較對象。故答案為A。