1 . 每个人都应当为保护环境做贡献。(make contributions to)(汉译英)

2 . I think the trouble will clear up in a couple________ days. （用适当的词填空）

3 . She stared at the girl as if seeing her ________ the first time. （用适当的词填空）

4 . They did not have enough staff, and the laboratory ________ which they worked had poor air quality. (用适当的词填空)

5 . “Are you really an artist?” Sara asked _______of curiosity.(用适当的词填空)

6 . There is no reason to be pessimistic ________ the future. (用适当的词填空)

7 . What will life consist ________ on other planets?(用适当的词填空)

8 . Do you remember the day when we chatted ______ each other all night? (用适当的词填空)

9 . Though it took place by________(偶然), we should be aware of the essence of it. （根据汉语提示单词拼写）