We should spend as much time as we _______ over our lessons.

Many students are          about football． They          play a game whenever possible．  

— I regret to say that I          have shouted at you the other day．
— Forget it． I was a bit out of control myself．  

––– I promise my daughter ____ get a nice present on her birthday.
––– I think it will be a big surprise to her.

Not having work out the problem,          leave the office．

If people eat natural poisons by mistake, they ________ go to hospital without delay.

—Listen! There is a knock on the door. Who _____ it be?
—It must be Jack. Just now I sent for him.

According to the school rules, no student _______ go out of school without the permission
of the teachers.

If the students who killed themselves had only been more confident, their deaths ________.

With time _______ by, he began making films.