When did you buy this computer? It looks so new.—I it for only a couple of days. My sister bought it for me as a birthday present.

All the ingredients are in the bowl. Please mix __.

Listen ! Helen is singing in the next room.—It __________ be Helen. She is in Tianjin now.

_______are you going to see your mother?—By train.

The new school is _____ our previous one.