— Look! The girl with long hair is making a snowman. Is she Sandy?— It __________ be her. I’m not sure.
Could you tell me ______?
---- Could you tell me how long ______ the book? ---- Three days.
When you see the sign “EXIT”, you know you can ________ from here.
---- How much did your bike _______? ---- I ________400 yuan for it.
Remember not to speak ________ when we are in the reading room.