It's very cold in the room.They ______ off air conditioner.A.should have turnedB.must have turned C.should turnD.must turn答案是B，A错在哪里
问题描述：
It's very cold in the room.They ______ off air conditioner.
A.should have turned
B.must have turned
C.should turn
D.must turn
答案是B，A错在哪里
答
b
答
B
答
应该选择B，意思是：屋里太冷了，他们一定是关掉了空调。must have 过去分词，表示对过去发生事情的推测。
答
turn off 关掉
答
turn
房间里面很冷.他们关掉空调
答
turn
turn off 关上，关闭
答
C