Unit13SectionB第一题答案
1. recycle
2. gate
3. bottles
4. president
5. metal
Unit13SectionB第二题答案
1. throw away
2. put sth.to good use
3.pull down
4. upside down
5. bring back
6.set up
Unit13SectionB第三题答案
Unit13SectionB第四题答案
Unit13SectionB Self Check第一题答案
1. longer
2. doing
3. going
4. regularly
5. medicine
6. first
7. beautifully
8. medical
9. development
10. business