1. Remember to _____ the lights when going out. This is the simplest to way to save electricity. A. turn on B. turn off C. put off D. go on 2. In my country, it is a tradition that the young _______ the old in the family. A. take care B. turn down C. look after C. grow up 3. My children have all ______ and left home now. A. grown up B. looked after C. turned off D. gone off 4. The residents around the area _cleaned off_ the beaches after an oil spillage. A. call off B. keep up C. put off D. cleaned up 5. We had to turn _______ their invitation to lunch as we had a previous engagement. A. over B. out C. up  D. down