What troubled the teacher was that no one present made an answer when asked who had broken the glasses, so he didn’t know who .
A. was blamed
B. was to be blamed
C. was to blame
D. would be blamed
网友回答
A. was blamed
B. was to be blamed
(答案→)C. was to blame
D. would be blamed
解析：
这题考查固定短语：be to blame“应受责备”，句意是：让老师感到麻烦的是，当问及谁打坏了眼镜时，在场的人没有回答，所以他不知道该责备谁。选C。