You are tired. You _____ go to bed early.

Food safety is important. Rules____ to stop people from food pollution.

—May I smoke here，please?—I am afraid you           ．This is a non-smoking area．

 When I lived with my roommates in the university, we ________ often talk into the night.

—_______ I take the newspaper away, please ?—No, you mustn’t. You _______ only read it here.