Complete the sentences with the given words.

1. It is important to ... paper, glass, and metal to protect nature.
2. Factories and cars cause a lot of air ... .
3. Many animals die because they eat ... from the ocean.
4. The Earth's ... helps keep us warm but is changing because of climate change.
5. If we burn too many ... , the planet will become hotter.
6. We need to reduce the amount of ... we throw away every day.
7. The ... in big cities makes it difficult to see the sky clearly.
8. The number of electric cars is starting to ... as more people care about the environment.