Across
- 4. the surface of the earth
- 5. use waste or chemicals to make rivers and seas dirty
- 6. the power from sources such as the sun, water, wind and coal
Down
- 1. an area to grow crops
- 2. a very high area of land with steep sides
- 3. the parts of a tree with leaves, flowers, or fruit on them
- 7. something like air, not liquid or solid