Question

7. We   for the spring outing last week had it not been for the heavy fog.

A. would go         B. could go

C. could have gone    D.  must have gone

Answer 1

7.    C考査虚拟语气。句意：要不是由于大雾，上周我们本来可以出去春游的。if引导的非真实条件句表示对过去的虚拟时用had done，主句用would/could/should/might have done;可以把if省略，将had提到从句句首构成倒装。而must have done表示"过去一定做了某事"，是对过去的肯定推测。因此选C