The ozone layer that protects life on Earth

Question

2. The ozone layer that protects life on Earth from harmful UV rays is showing promising signs of recovery, according to a report issued by the UN Environment Program and the World Meteorological Organization. Although levels of ozone depletion remain high, the rate of depletion has not increased for over a decade and in some places there are signs of the layer thickening.

Which of the following, if true, most strengthens the above argument?

A. CFCs and similar compounds deplete ozone because when they reach the stratosphere, UV light breaks them down to release chlorine or bromine atoms, which in turn form active species that react with ozone.
B. Although the most potent ozone-depleting compounds have been phased-out and their emissions have declined considerably, many of them are quite inert and it will take between years and centuries before they are fully removed from the atmosphere.
C. Current depletion is still high but has not gotten worse for over a decade now.
D. The latest report compiled by around 300 scientists as part of an Ozone Treaty requirements suggests that the ozone layer is on course for recovery thanks to the ban of culprit chemicals.
E. About 90 percent of CFCs currently in the atmosphere were emitted by industrialized countries in the Northern Hemisphere, including the United States and Europe.

GSBae · Answer

A - just discusses how the ozone breaks down - not relevant. 
B - weakens the argument. 
C - just a restatement of what's in the prompt. 
D - states that ozone layer is on course for recovery AND STATES WHY. 
E - just states where the culprits are coming from - not relevant.

Answer: D

chesstitans · Answer

lesson here: an evident outside of the passage can be considered a right answer.

rohitkabra1987 · Answer

Can anybody please explain the problem with option b .thank you !

AbhiGarg2007 · Answer

The ozone layer that protects life on Earth from harmful UV rays is showing promising signs of recovery, according to a report issued by the UN Environment Program and the World Meteorological Organization. Although levels of ozone depletion remain high, the rate of depletion has not increased for over a decade and in some places there are signs of the layer thickening.

Which of the following, if true, most strengthens the above argument?

A. CFCs and similar compounds deplete ozone because when they reach the stratosphere, UV light breaks them down to release chlorine or bromine atoms, which in turn form active species that react with ozone.
B. Although the most potent ozone-depleting compounds have been phased-out and their emissions have declined considerably, many of them are quite inert and it will take between years and centuries before they are fully removed from the atmosphere.
C. Current depletion is still high but has not gotten worse for over a decade now.
D. The latest report compiled by around 300 scientists as part of an Ozone Treaty requirements suggests that the ozone layer is on course for recovery thanks to the ban of culprit chemicals.
E. About 90 percent of CFCs currently in the atmosphere were emitted by industrialized countries in the Northern Hemisphere, including the United States and Europe.

IMO: B

Argument:- Level of depletion is high but rate has not increased. Option B suggests that MOST Potent chemicals have been phased out so rate is not increasing but since after-effects still exist so level of depletion is high.

Experts plz validate!

abhimahna · Answer

Hi rohitkabra1987 / AbhiGarg2007 , Here I go: The argument is saying the Ozone layer is showing recovery. Although it is still at high level, the depletion has not increased over the past decade. We need to strengthen this. We can find out something that shows positive impact. A. CFCs and similar compounds deplete ozone because when they reach the stratosphere, UV light breaks them down to release chlorine or bromine atoms, which in turn form active species that react with ozone. --> How CFCs and others are depleting is OFS. B. Although the most potent ozone-depleting compounds have been phased-out and their emissions have declined considerably, many of them are quite inert and it will take between years and centuries before they are fully removed from the atmosphere. --> It is a weakener actually. It is saying even if you stop the emissions, it will take centuries to recover. While the argument said change over a decade. Hence, saying this would mean what the argument is saying is incorrect. C. Current depletion is still high but has not gotten worse for over a decade now. --> We already know this. Nothing new. D. The latest report compiled by around 300 scientists as part of an Ozone Treaty requirements suggests that the ozone layer is on course for recovery thanks to the ban of culprit chemicals. --> It is saying we found some reports proving what we concluded. Hence, a strengthener. E. About 90 percent of CFCs currently in the atmosphere were emitted by industrialized countries in the Northern Hemisphere, including the United States and Europe. --> Who is emitting those emissions is OFS. Feel free to ask 'n' number of questions.

broall · Answer

The question asks for the answer that strengthens the argument.

In choice B, since it could take centuries to fully remove potent ozone-depleting compounds from the atmosphere, it's clear that those chemical compounds would depleting the ozone layer. Hence, this choice clearly weakens the argument that there are evidences showing promising signs of recovery of ozone layer. Thus, choice B is incorrect.

VerbalBot · Answer

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The ozone layer that protects life on Earth

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The ozone layer that protects life on Earth

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