,Unit 2 Heroes,答案：worked 2Did you speak with the boss? No，when I arrived，he _(talk)，so I had no chance. 答案：was talking,3If it _(stop) snowing, Ill go to the park. 答案：has stopped 4It is the second time that I _ (make) the mistake. 答案：have made 5You know，I _(meet) my girlfriends parents for the first time only yesterday. 答案：met 6Three days later，in the middle of the night，he _(hear) Joes voice. 答案：heard,7The boys in my class often _(joke) about her and laughed their heads off. 答案：joked 8One morning，I _(wait) at the bus stop，worried about being late for school. 答案：was waiting 9Since I was born，I _(receive) a good quantity of gifts. 答案：have received 10Since the first Earth Day in 1970，Americans _(get) a lot “greener” toward the environment. 答案：have gotten,去掉have,goneaway,whilewhen,hadhas,去掉第二个has,as soon as,enjoy oneself,protect environment,not only.but also.,All the way up, we sang happily.,After we had our picnic at noon we organized an activity, talking to the visitors about the importance of protecting the environment.,We not only had a good time but also did a good deed today.,Tired though I am now, I feel quite happy.,