Unit 11 Yang Liwei’s Mission to Space
3. _____are useful animals. a. cow b. pig c. panda d. sheep 4. be careful when _____the street. a. to cross b. cross c. you cross d. you’ll cross 5. take your time, _____you’ll make another mistake. a. then b. and c. if d. or 【參考答案】 1. c 2. d 3. d 4. c 5. d