1 . 这种物质在动物实验中效果很好，但他们必须知道它对人类是否安全。(汉译英)

2 . I thought you might like something to read, ________   I have brought you some books. (用适当的词填空)

3 . You should be more careful when you are driving, ________ you might have an accident. (用适当的词填空)

4 . I’m interested in performing ________ it’s my dream to be an actor. (用适当的词填空)

5 . He was very busy yesterday, o ________ he would have come to the meeting. (根据首字母单词拼写)

6 . There was not as much homework as I was used to, __________it was still challenging. (用适当的词填空)

7 . 写出while在句中的用法
1. While I was watching TV, the bell rang.________________________
2. While a great many people like the convenience of using WeChat to communicate with each other, too many junk messages on it may make them bored.________________________
3. He went out for a walk, while I stayed at home.________________________

8 . Mama gave him a bright smile________wrote down a number.(用适当的词填空)

9 . I realize the secret to success is not when and where you were born, ______ what you are doing in your life. (用适当的词填空)