Here are the correct forms of the words in brackets:

1. Many cleaning products contain harmful **chemicals**. (chemistry)
2. Fish and many other animals are killed by **pollution** in their habitat. (pollute)
3. We should avoid buying single-use **produces**. (produce)
4. Many species of plants and animals are in danger of **extinction**. (extinct)
5. We can protect the environment by **picking** up rubbish. (pick)
6. Light pollution makes us **unable** to see the stars in the sky. (able)
7. Finding a balance between what humans and animals need will help prevent habitat **destruction**. (destroy)
8. Monarch butterflies are now a(n) **endangered** species due to declining numbers. (danger)

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