—It ____ be Amy. None of us except her is able to do it.
—No, it isn't. It ____ be Anne's. I see her name on it.
can't ; needn't; mustn't; must
—Yes. The food there be delicious.
—No, you . You can clean it after school.
—It ____ be very expensive. I never even dream about it.
—Certainly. But you ____ be back by ten o'clock.