—What are you doing this Saturday?—I’m not sure,but I________go to the Rolling Stones concert.
24. Who is it up ____ decide whether to go or not?
23. Wang Mei is one of many Chinese teenagers _____ “on the go”
35. He was born ____ a very cold night _____ December.
34. When he knocked at the door, my mother was busy ____ supper.
33. He waited until it was dark ____ nobody could see him clearly.