Although medical science _____control over several dangerous diseases, what worries us is that some of them are returning.

What should we do for the disabled children in the Children’s Home—You’re supposed to _________ a study group to help them.

The newly-built house, the walls _______ are painted light green, is really a peaceful place for us, especially after hard work.

Sorry, sir. I made a mistake again.–_________. Practice more and you will do better.

It’s nearly eight o’clock. They______ be here at any moment.