Sanya is a beautiful city. There are many people here _________vacation every year.
---Could you please come to the museum with me this afternoon? ---Sorry, I ______ . I have to take a piano lesson at 2 pm.
--- Lin Tao, can I use your English dictionary? --- Sure. But you _______ return it before the class.
You_______ play with the knife. You ______ hurt yourself.
— It seems that Mr. Wu is standing there. — It ______ be him because he called me from Canada just now.
—Will you please answer the door? It ________ be your sister. —Sorry, I ________. I’m feeding the rabbit.