Proficiency environment

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Across
  1. 6. make something start to happen
  2. 7. (of an animal) that brings up the food from its stomach to chew again
  3. 8. burn something until it is destroyed
  4. 9. real, concrete
  5. 10. the process of making somebody weak
  6. 12. uncontrolled
  7. 13. a chemical used for killing unwanted plants
  8. 17. a written agreement between countries
  9. 19. bare and lifeless
  10. 20. the transformation of fertile land into desert
Down
  1. 1. consequence
  2. 2. the act of getting rid of waste, etc
  3. 3. the cost of keeping a park/building/etc in good condition
  4. 4. contaminated
  5. 5. harmful
  6. 11. the loss of plants in an area due to excessive feeding by animals such as cows
  7. 14. the place where a river joins the sea
  8. 15. destroy something completely
  9. 16. the gradual destruction of metals due to water or chemicals
  10. 18. give somebody confidence to do something