一、单项选择。(15) 1. If you want to listen to music , . A. turn it down B. turn it off C. turn it on D. turn on it 2. You must the traffic when you walk across the street. A. look out of B. look down on C. look down at D. look out for 3. We are not sure ______ he will come here tomorrow or not. A. that B. whether C. if D. what 4. When did your book ________? A. come out B. come on C. come to D. come in 5. ---