It is usually not quite cold in this area in March, but sometimes temperature ____be very low.

Without your help, I ＿＿＿＿the exam last term. 

—What would you wish to do if you were a college student again? —That's very hard to say, but I wish I___________ when I was a college student.

---Mike must have known that.---No, he ________. How _______ he?

I was caught in a traffic jam for over an hour, otherwise I ________ you waiting for such a long time.