Question

--- You ______ your ideas at the meeting in a different way.
--- Thank you, but I was too angry then.

1. A.
   must express
2. B.
   could express
3. C.
   could have expressed
4. D.
   must have expressed

Answer 1

C
试题分析：句意：—在会议上你本来可以用不同的方式表达你的想法。---谢谢你，但那时我太生气了。 由but I was too angry then 可知是过去时态，所以过去能够做而没有做的，用could have done表示。must have expressed表示对过去的肯定推测。A、B都是对现在时间的推测。故选C。 
考点: 考查情态动词的用法。