问题补充:
David did not regret saying what he did but felt that heit 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:考查虚拟语气。根据did说明本句是对过去情况的虚拟,故使用情态代词+have done,排除AB。D想是对过去情况的推测,而不是虚拟。Could have done本可以做某事,实际上却未做。句意:David不后悔说他所做的,但是感觉他本可以用另外一种方法来做。故C正确。