问题补充:
He did not regret saying what he did but felt that he it differently.
A. could express
B. would express
C. could have expressed
D. must have expressed
答案:
A. could express
B. would express
(答案→)C. could have expressed
D. must have expressed
解析:考查情态动词+have done的用法:could have done本可以做而没做,must have done过去一定做了,句意:他不后悔做得事情,只是感觉他可以做得更好(而实际没有)。选C。