Sustainability

7. Not able to grow again or be made again.
9. To use (something) again
13. To make something new from (something that has been used before)
14. A black or brownish-black hard substance within the earth that is used as a fuel
15. Energy that is created when the nuclei of atoms are split apart or joined together
17. Food has this kind of energy.
19. Usable power that comes from heat, electricity, etc.
23. A situation in which too many people or animals live in a certain area
25. Using the sun's light or heat
26. An engine that has a part with blades that are caused to spin by pressure from water, steam, or air.
27. A machine that change electric energy into kinetic energy.
28. To catch too many fish so that there are not enough remaining.
29. A thick, black liquid that comes from the ground and that is used in making various products (such as gasoline)

1. Able to last or continue for a long time.
2. Lightning has this kind of energy.
3. Heat energy
4. The production of electricity by using machines that are powered by moving water.
5. The mechanical energy that is stored.
6. A machine that change kinetic energy into electrical energy.
8. No longer existing.
10. A material (such as coal, oil, or gas) that is burned to produce heat or power
11. Able to be replaced by nature before being used up.
12. To make (something) smaller in size, amount, number, etc.
16. Its spectrum includes radio, microwave,infrared, visible light, UV light, X ray and Gamma.
18. A piece of material (such as iron or steel) that is able to attract certain metals
20. Using the natural heat produced inside the Earth.
21. The action or process of making land, water, air, etc., dirty and not safe or suitable to use.
22. The mechanical energy that is moving.
24. The flow of the ocean's water as the tide rises or falls