问题
选择题
– Mary was crying sadly.
-- Oh, she ________ the bad news that her mother was badly injured in the accident.
A．must know
B．might have known
C．must have known
D．should have known
答案
答案：C
考查虚拟语气.句意:玛丽哭得很伤心._哦,她一定是知道了她的母亲在车祸中严重受伤的坏消息了. “must+have+done”表示对过去事情的肯定推测，译成“一定做过某事”，该结构只用于肯定句。结合语境可知选C.