1. three 　2. first　 3. middle　 4. family　 5. first (given)　 6. family　 7. first　 8. from　 9. For　 10. Dave　 11. Lin　 12.　 Sue　 13. short　 14. why　 15. Because

10.If you can't speak English，say it in Chinese.

9．　 They must both go to school at once. It's eight o'clock already.

8．　 Best wishes to you.

7．　 What's the weather like today?

6．　 You'd better not go out. It's raining heavily.

5．　 His name is Mike Jackson，so we often call him Mr. Jackson.

4．　 I left my homework at home and I have to go and get it before class.

3．If you are late for school，you must say sorry to the teacher.

2．Lesson Four is the hardest lesson in Junior English Book Two.