1. Conservationists/conservation
2. Unpoluted
3. Careless
4. Prohibition
5. Disappointed
6. Câu này từ trong ngoặc hình như sai ạ
7. Invention - achievements
8. Solution
9. Excitement
10. Valuable
11. Coastal
12. Sightseer
13. Enthusiastic
14. Disappointing
15. Poluted
16. Environmentalists
17. Polluted
18. Sewage
19. Polluted
20. Complanation