From the tears in his eyes we can tell that something sad ________
A、might occur
B、would have occurred
C、should occur
D、must have occurred
【正确答案】：D
【题目解析】：Must have done表示肯定发生了什么事。此句的意思是看他眼里的泪水我们可以判断肯定有什么不好的事发生了。表肯定推测时一般用情态动词must+ have done/be，表否定的推测时一般用can’t be或couldn’t have done.
