Hey, Mary, your backpack looks nice. When did you buy it. — I ____ it for two weeks.

They both have some friends; but his ____more active.

The science of computer, ______ rapid progress has been made in recent years，plays a very important role in our daily life.

You seem to be burning yourself out with thecoming exam!—–________. I’m dying for a thorough rest and a goodworkout.

go Dutch for this supper, OK–No, _______ this time, as a reward for all your help