It is no doubt that Liu Xiang is _______ favorite star.

I’m sorry I can’t find the library book anywhere.— So…I’m afraid you have to _________ it.

David talked with a friend of ____ on the Internet for a long time yesterday.

I don’t think it very expensive to buy a family computer here.—Really? I’ll buy _____ next week.

Drinking water in summer _____ your health.[ ]