Question

If they had known what was coming next, they __ their mind.

A. may change
B. could change
C. must have changed
D. might have changed

Answer 1

答案D
考查情态动词。if引导的条件状语从句与过去是相反，主句中要用would/should might have done. 而must have done表示一定已经做了某事。