问题
选择题
_____ seems difficult________ who broke the window.
A．This;to find out
B．It;to find out
C．That;finding out
D．It;finding out
答案
B
题目分析: 句意: 找出谁打破窗户似乎很困难。It seems +adj+to do做某事似乎……的，固定句型，it 为形式主语，to do不定式做真正主语，故答案选B.