Where did you go on vacation –I ___________.

It’s too hot. Why not go swimming with us– ____

I regret _____ you that Mary was badly injured in theaccident.—I can hardly believe my eyes. She is always socareful.

Who, _____ is the most popular teacher in our school—I think it’s Mr．Zhang.

当别人称赞你时, 你应该说: “____”。