Across
- 2. The ground, the top layer of earth in which plants grow
- 4. Devices that regulate direct or control the flow of a fluid by opening and closing
- 7. Harmful or poisonous substances introduced into the environment
- 8. A turbine that is powered by wind
- 10. Thanks to this you feel warm under your feet - … heating
- 11. A barrier constructed across a waterway to control the flow or raise the level of water
Down
- 1. The pipes, fixtures; and other apparatus of water, gas, or sewage system in a building
- 3. A large kettle or a boiler
- 5. A system for supplying heat, especially central heating, to a building
- 6. A regular removal of garbage
- 9. Liquid and solid waste carried off in sewers or drains