Question

short for chlorofluorocarbons, cfcs are chemical compounds. scientists developed cfcs to replace toxic elements used in refrigeration. cfcs started being popularly used in the early twentieth century. these were used in refrigeration units and aerosol cans. at that time, it was not known that cfcs combine with ozone in our atmosphere and weaken the ozone layer. the ozone layer is important to earth in protecting it from the ultraviolet rays of the sun. because the ozone layer is weakened by cfcs, more living beings on earth are being exposed to the strong ultraviolet rays. the use of cfcs has declined. however, because it has remained in the atmosphere for nearly a century, much damage has been done to the ozone layer.
the passage is organized using the structure of
a. definition.
b. classification.
c. cause/effect.
d. compare/contrast.

Explanation:

The passage first introduces CFCs, then explains that their use (cause) leads to ozone layer weakening, which in turn exposes living beings to harmful UV rays (effects), and notes the lasting damage from their atmospheric persistence. This follows a cause/effect structure.

Answer:

C. cause/effect.