题目内容
–Listen! Helen is singing in the next room. -It ___ be Helen. She has gone to Beijing.
A. can’t B. mustn’t C. may D. should
练习册系列答案
相关题目
题目内容
–Listen! Helen is singing in the next room. -It ___ be Helen. She has gone to Beijing.
A. can’t B. mustn’t C. may D. should