题目内容
13、______ that the air conditioners cause so much pollution, I would never have bought one.
A. If I knew B. Did I know C. If I have known D. Had I known
试题答案
13、D
相关题目
______ that the air conditioners cause so much pollution, I would never have bought one.
A. If I knew B. Did I know C. If I have known D. Had I known
查看习题详情和答案>>