Question

________ he driven more carefully, the accident would not have happened the other day.

1. A.
   Be
2. B.
   Had
3. C.
   Has
4. D.
   Would have

Answer 1

B
解析：
考查虛擬語氣。“如果他開車在小心一點(diǎn)，事故就不會發(fā)生了�！备鶕�(jù)主句的would not have happened可知，與過去相反，故用過去完成時(shí)，即If he had driven...，If引導(dǎo)的虛擬語氣常用省略形式，把had提前，即Had he driven...。故選B。