【题目】—Did you make it at last?
—Yes. But for your help , it ________a serious loss.
A.would cause
B.must have caused
C.would have caused
D.may cause

【答案】C
【解析】考查虚拟语气。答句第二句为含蓄条件句，but for引出虚拟条件，此处表示对过去情况的虚拟，故句子谓语形式为would/should/could/might have done。根据句意可知选C。