I really didn’t know who for the broken window for none of them admitted that he had done

问题补充：

I really didn’t know who for the broken window, for none of them admitted that he had done it.

A. to be blamed

B. is blamed

C. to blame

D. being blamed

答案：

A. to be blamed

B. is blamed

(答案→)C. to blame

D. being blamed

解析：这题考查词组：be to blame“应受责备”，句意是：我真不知道打坏的窗户要责备谁。因为没人承认谁做了。选C。