Finally he reached a lonely island ________ was completely cut off from the outside world.

Smart phones are more and more popular now.—So they are. But they still ______ too much.

Tony, are you listening to me?—Sorry, SirI ______ to figure out what you said just now

Do you go to school ____________ your father’s car— No, I go to school ____________ bus.

In our class, the student leaders are on dutyevery few days.