Complete the sentences using the comma where necessary. 1. If people

1. If people think more about ecology, our planet will be saved. 2. The air will become cleaner when we solve this problem. 3 The factory won't pollute the environment if we use filters. 4 If children take care of animals,  they won't die in the winter . 5 Wild animals won't be endangered if people don't destroy their habitats. 6. When I come to the country, I'll enjoy the fresh air . 7. They will see many species of mammals when they visit the local zoo.