---Must he remember everything he has learned in the class?---No, he _____.

It is usually warm in my hometown in March, but it _____ be rather cold sometimes.

On rainy days, accidents ______ happen sometimes on steep roads．

How ________ I help them to understand when they don’t listen?

–Why don’t you stay at the Baotuquan Hotel?  --You      ! Do you know how expensive that place is?