Thank you for helping me a lot.—_________________. That’s what friends are for.

He is a_______, and he works in Beijing Hospital.

Do you know that umbrellas are provided for free at the underground station—Yes. But we return it in a week， or we’ll pay for it.

If there ______no buying and selling of animals, there______no killing in nature.

We advise parents _____ their children at home alone in order to keep them away from danger.