问题
选择题
David 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
答案：C
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。