II. Fill in the words from exercise I.

II. Fill in the words from exercise I.

1. 11) Please, do not drop litter in the park.
2. 12) We should pick up rubbish to make our school yard beautiful.
3. 13) Let's keep the street clean to keep the street clean.
4. 14) Our planet is in danger because of pollution.
5. 15) Ecology teaches us how to protect nature.
6. 16) Dirty water can kill fish and other animals.
7. 17) We must protect nature for future generations.