文档介绍：Key Unit 1 AABAC CDDAB Unit 2 BCDAC CDCBA Unit 3 DCDDC BDACB Unit 4 ACCBA BACAC Unit 5 BBBAC DDDAB Unit BDB ABCAA Unit 7 ACDBC ACBBC Unit CBC DBCAC Unit 9 BDCAA BBBBD Unit 10 BCCAA ACABB Unit 11 BAABC DBABD Unit 12 BACBB ACDBB Unit 13 DCDCA DABCB Unit 14 BADAB ABABD Unit 15 DCBBA CDAAB Practice 1 10. B 11. C 12. D 13. A 14. A 15. A 16. B 17. B 18. D 19. D 20. C Practice2 10. A S1. focused S2. emotionally S3. distant S4. cancer S5. retirement S6. crossed S7. increasingly S8. Regardless of your age, you can make a number of important changes in your current life style. S9. We know much more about preventive health today than our parents and grand parents did in the past. S10. and this new knowledge can be transmitted to our children to help them e healthier than our generation . Practice 3 10. C 11. D 12. C 13. A 14. D 15. C 16. A 17. B 18. B 19. D 20. A Practice S1. mysterious S2. coupled S3. ruining S4. percent S5. species S6. ensure S7. average S8. When you consider that equals a quarter of the world catch, you begin to see the size of the problem. S9. some countries are beginning to deal with this problem, but it’s vital we find a rational way of fishing S10. It would make sense to give the fish enough time to recover, grow to full size