Thanks for the question! We’re asked here for something that would most strengthen M&R’s argument about the long-term effects of CFCs in the stratosphere. Step one: figuring out what this argument is. Take a look at the third paragraph. There, we’re told that long-term effects would be depleting the ozone layer, even if CFCs stopped going into the atmosphere. So we want something that would help support this idea.
Now let’s take a look at (A), which tells us that an ozone hole over Antarctica kept growing, even though CFC emissions stopped. Well, that’s pretty direct evidence of what M&R were arguing, and so is a good strengthener. Definitely hold on to it, and it ends up being the best of all the answer choices, so it’s the correct answer.
Now let’s take a look at (C), which says that ozone reacts more violently with chlorine than with many other chemicals. OK, but so what? “Many” other could be 3 or 4 others, and “more” could be a fraction more. That doesn’t strengthen nearly as much as (A) does, and so (A) is correct.
Hope this helps! Feel free to ask any other questions that you might have.
JosephHNovember 5 at 05:03PM
But it didn't say that the CFC emissions stopped. It said they "almost ceased." Wouldn't the ozone hole be expected to keep growing if CFC emissions were still being released? I thought that the "almost" was a qualifier that made this answer wrong. Was I giving it too much weight?
