It was when she was sleeping in her bedroom a thief broke into the house.
A. which
B. that
C. where
D. than
网友回答
A. which
(答案→)B. that
C. where
D. than
解析：句子去掉It was和 之后，剩下a thief broke into the house when she was sleeping in her bedroom.是一个完整句子，所以原句是强调句型，选B。