种植银杏树前景:英语高手请进。。。

来源:百度文库 编辑:中科新闻网 时间:2024/05/11 03:56:15
He said that the driver must have had an accident;otherwise he___
by then.

A:would have arrived B:must have arrived
C:should arrived D:would arrive

请解释答案并给出“虚拟用法”的相关知识。谢谢!!