The cleaners should not be looked down on and they are angels of the city _________.
—What are you in?—I’m in Three.A.class, class B.class, Class C.Class, Class
—Must we keep the window _______ all the time? —No, you don’t have to.
We _______ play on this road. There is too much traffic.
The old man was _______ sad _______ say a word when he heard the bad news.
—Why do you like living in the countryside?—Because there’s _______ noise and _______ cars there.