Earth Day is celebration of life and our planet. It is a reminder that we need to ________the world we live in and that we should learn to respect life and nature.
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.