问题
选择题
---You ought to have warned him of the danger!
--- ____! But he wouldn’t listen!
A．So did I
B．So ought you
C．So I did
D．So I have
答案
答案：C
句意：你本应该警告他有危险！我第五警告了，但是他不听。ought to have done 本该做某事而实际上没有做，so + 主语+ 助动词，表示对上句的肯定，根据语境警告的动作在过去所以用助动词did，故选C。