Unit 12 Reading 2

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Across
  1. 3. A puzzling question, person, or thing that is difficult to understand
  2. 6. To keep safe from harm, injury, or damage
  3. 8. A system of parts working together, or a process by which something takes place
  4. 10. Resistant to a particular infection, toxin, or penalty
  5. 11. The act of making a change or modification
  6. 17. Decided or established in advance
  7. 18. The quality of being new, original, or unusual
  8. 19. To completely remove or get rid of something
  9. 20. To a great or significant degree; considerably
Down
  1. 1. To increase rapidly in numbers or multiply
  2. 2. To move from one region or habitat to another
  3. 4. Causing confusion, bewilderment, or difficulty in understanding
  4. 5. To escape or avoid someone or something, especially by cleverness
  5. 7. Required by law, rule, or authority; compulsory
  6. 9. The smallest structural and functional unit of an organism
  7. 12. To enter a place or situation where one is unwelcome or uninvited
  8. 13. To improve something by making small changes, or to remove impurities
  9. 14. To give all or a large part of one's time or resources to a cause or person
  10. 15. To insert or fix firmly into an area, tissue, or person's body
  11. 16. To make previously unknown or secret information known to others