Which of the following most logically completes the passage? Leaf beetles damage willow trees by stripping away their leaves, but a combination of parasites and predators generally keeps populations of these beetles in check. Researchers have found that severe air pollution results in reduced predator populations. The parasites, by contrast, are not adversely affected by pollution; nevertheless, the researchers’ discovery probably does explain why leaf beetles cause particularly severe damage to willows in areas with severe air pollution, since ________. (A) neither the predators nor the parasites of leaf beetles themselves attack willow trees (B) the parasites that attack leaf beetles actually tend to be more prevalent in areas with severe air pollution than they are elsewhere (C) the damage caused by leaf beetles is usually not enough to kill a willow tree outright (D) where air pollution is not especially severe, predators have much more impact on leaf-beetle populations than parasites do (E) willows often grow in areas where air pollution is especially severe ID: 500265

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Leaf beetles damage willow trees by stripping away their leaves, but

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Elite097

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09 Oct 2022, 22:10

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avigutman KarishmaB but based on what happens in areas with no sever pollution how can e conclude about areas with pollution? We have these kidn of answers wrong in most cr questions generally right?

KarishmaB

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avigutman KarishmaB but based on what happens in areas with no sever pollution how can e conclude about areas with pollution? We have these kidn of answers wrong in most cr questions generally right?

Hard to make rules. Every question is different. Here it makes complete sense because it tells us that when pollution is not a major factor, predators have a much bigger role to play. So if predators are impacted (by pollution), beetle population might get out of control.

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10 Oct 2022, 08:14

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avigutman KarishmaB but based on what happens in areas with no sever pollution how can e conclude about areas with pollution? We have these kidn of answers wrong in most cr questions generally right?

You've got a point here, Elite097. If we ONLY had information about what happens in areas with no severe pollution, it would be very difficult to make any inferences about what happens in areas with severe pollution.
However, that's not the case here. We also know that severe air pollution results in reduced predator populations, and that the parasites, by contrast, are not adversely affected by pollution.
Why, then, might it be helpful to get some information about areas with no severe pollution? If you can answer that, you'll learn something valuable from your mistake.