According to the latest study，most traffic accidents     be prevented if drivers are careful enough．

 — Are you going to Beijing by air?— It’s fast, but expensive. So I’m not sure. I _____ take a train. 

 As to the question of whether we will sell our house or who we shall sell the house to, you ____ have answer by tomorrow.

You'd better ____ football in the street.

_Could I go to the movie this Sunday, Dad?Yes, you_____. But you ______ come back before nine.