【题目】－The zookeeper was really annoyed with me.
－How could he have been if you ____ stones at the animals?
A. didn’t throw B. don’t throw
C. hadn’t thrown D. haven’t thrown
在线课程【答案】D
【解析】试题分析：考查现在完成时。句意：动物管理员真的让我生气，如果你不向动物扔石头会怎么样呢？have not been可以是假如原来怎样，故选D。