1
														2					3
								4			5						6
7
									8
			9		10
								11
12
			13
													14
		15
							16						17
		18								19
	20
	21

Across 4. Describing the range or variety of plant and animal life. 7. A disease caused by mosquitos. 8. Describing something that works very well. 12. Describing a disease that can be passed from one person to another. 13. Describing a species that has completely disappeared from the earth. 14. The place where animals live. 16. Describing a part of the world that is hot and humid. 18. A large farm, often a monoculture of plants such as palm oil. 20. A huge epidemic. 21. Damage or lower the quality of soil, especially through overuse.

Down 1. The official word for 'corn'. 2. Can be depended on to work well or keep a promise. 3. A gas produced by electrolysis. 5. Cutting down trees. 6. Not working steadily all the time. 7. Growing the same crops in the same place year after year. 9. Wood (usually commercially valuable) 10. Describing water systems for drinking, washing, toilets and drains. 11. A large farm, usually for beef cattle. 15. Neither hot nor cold. 17. Describing land that is suitable for growing crops. (Not animals). 19. Very overweight.