He worked out such different questions at a very young age.— Oh, he ______ a very smart student then.

We’ll go to the park unless it ____tomorrow.

At the science museum，the boys and girls get to know__________.

Look, here’s an English book on the desk, Is ityours — No, it isn’t _______. It must belong to _______.

My brother likes fruit a lot and he eats it three ________ four times every week.