问题补充:
It is not I but Tom and his wife that for the car accident.
A. am to blame
B. are to blame
C. am to be blamed
D. are to be blamed
答案:
A. am to blame
(答案→)B. are to blame
C. am to be blamed
D. are to be blamed
解析:强调句型,强调部分为not…but…, not…but…连接两个名词作主语时谓语动词与but后面的主语保持一致;sb be to blame主动表被动,因此选B。