Mr. Smith ________ from here for three months. He’ll return in a week.

Some children are too selfish today. They should be taught to _____things with others so that they will show concern for others.

Our teacher often tells us ____ the windows before weleave.

I’m worried about my English.—_____ harder, _____you will catch up with your classmates.

It was ______ computer games that cost the boy a lot of time that he ought to have spent on his lessons.