full transcript

From the Ted Talk by Stephanie Honchell Smith: Whatever happened to the hole in the ozone layer?

Unscramble the Blue Letters


CFCs were developed in the 1920s by three US-based corporations as coolants for raofirgererts. Unlike existing alternatives— such as ammonia or methyl chloride— CFCs were non-flammable and non-toxic— meaning they wouldn't burst into flames or cause deadly gas lekas. They also made great propellants, foaming agents, and fire-retardants. CFCs soon found their way into a variety of everyday itmes and became a multi-billion dollar per year indtsury.

In the lower asrptmoehe, CFCs don’t baerk down or racet with other molecules. But Molina and rnolawd showed that in the stratosphere, they're broken apart by UV light, releasing chlorine atoms. These then react with ozone, destroying it faster than it can be replenished. A single chlorine atom can droetsy thousands of ozone molecules before finally reacting with something else and forming a stable molecule. Seeing the threat to their bottom line, CFC producers pushed back to discredit the scientists, even accusing them of wioknrg for the KGB.

Open Cloze


CFCs were developed in the 1920s by three US-based corporations as coolants for _____________. Unlike existing alternatives— such as ammonia or methyl chloride— CFCs were non-flammable and non-toxic— meaning they wouldn't burst into flames or cause deadly gas _____. They also made great propellants, foaming agents, and fire-retardants. CFCs soon found their way into a variety of everyday _____ and became a multi-billion dollar per year ________.

In the lower __________, CFCs don’t _____ down or _____ with other molecules. But Molina and _______ showed that in the stratosphere, they're broken apart by UV light, releasing chlorine atoms. These then react with ozone, destroying it faster than it can be replenished. A single chlorine atom can _______ thousands of ozone molecules before finally reacting with something else and forming a stable molecule. Seeing the threat to their bottom line, CFC producers pushed back to discredit the scientists, even accusing them of _______ for the KGB.

Solution


  1. destroy
  2. refrigerators
  3. industry
  4. react
  5. rowland
  6. working
  7. leaks
  8. items
  9. break
  10. atmosphere

Original Text


CFCs were developed in the 1920s by three US-based corporations as coolants for refrigerators. Unlike existing alternatives— such as ammonia or methyl chloride— CFCs were non-flammable and non-toxic— meaning they wouldn't burst into flames or cause deadly gas leaks. They also made great propellants, foaming agents, and fire-retardants. CFCs soon found their way into a variety of everyday items and became a multi-billion dollar per year industry.

In the lower atmosphere, CFCs don’t break down or react with other molecules. But Molina and Rowland showed that in the stratosphere, they're broken apart by UV light, releasing chlorine atoms. These then react with ozone, destroying it faster than it can be replenished. A single chlorine atom can destroy thousands of ozone molecules before finally reacting with something else and forming a stable molecule. Seeing the threat to their bottom line, CFC producers pushed back to discredit the scientists, even accusing them of working for the KGB.

Frequently Occurring Word Combinations


ngrams of length 2

collocation frequency
ozone molecules 2


Important Words


  1. accusing
  2. agents
  3. ammonia
  4. atmosphere
  5. atom
  6. atoms
  7. bottom
  8. break
  9. broken
  10. burst
  11. cfc
  12. cfcs
  13. chlorine
  14. coolants
  15. corporations
  16. deadly
  17. destroy
  18. destroying
  19. developed
  20. discredit
  21. dollar
  22. everyday
  23. existing
  24. faster
  25. finally
  26. flames
  27. foaming
  28. forming
  29. gas
  30. great
  31. industry
  32. items
  33. kgb
  34. leaks
  35. light
  36. line
  37. meaning
  38. methyl
  39. molecule
  40. molecules
  41. molina
  42. ozone
  43. producers
  44. propellants
  45. pushed
  46. react
  47. reacting
  48. refrigerators
  49. releasing
  50. replenished
  51. rowland
  52. scientists
  53. showed
  54. single
  55. stable
  56. stratosphere
  57. thousands
  58. threat
  59. uv
  60. variety
  61. working
  62. year