Where is Jack.—–He______ be in the readingroom .I saw him just now.

It was when we were returning home ________ I realized what a good feeling it was to have helped someone in trouble.

Would you like to see a film with us this evening?-I’d like to.But I can’t__________the time because I have to finish my composition.[ ]

At present, more and more people prefer_________ in the countryside because there is _____ pollution in the city.

Students should by all means ______ their studies though there are a lot of attractions around them. [ ]