1. rivers

2. earth  The earth is a great place to live but people pollute it we need to make earth a better place to live we need to stop polluting the earth they are killing are trees and polluting the air with different gases in the o-zone.

3. safe  We need to keep the earth safe from tree killers and polluters they need to stop polluters from killing the earth.

4. environment  We need to protect the environment from polluters and animal killers and we are killing animals that live in the trees.