问题
选择题
– I ran 10 miles last weekend. Can you believe that?
– Wow, that ______ easy!
A．mustn' t be
B．mustn't have been
C．can't have been
D．couldn’t be
答案
答案：C
题目分析:考查情态动词。must 表示推测不用于否定句，排除A、B选项，而根据last weekend可知这是对过去的推测，应该用情态动词+have done，所以C选项正确。句意：--我上周跑了十英里。你相信吗？--哇，那肯定不容易吧！
