Logical reasoning PrepTest 131 · Section 2 · Question 10

Incorrect. The benefits of earthworms, which are destroyed by chemical fertilizers, are primary reasons why chemical fertilizers shouldn't be used—it's support for the main point.

Incorrect. This premise, coupled with the one about the benefits of earthworms, is primary support for the conclusion against the use of chemical fertilizers.

Incorrect. This statement is a premise that explains how earthworms are beneficial to soil.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Main Point

Stimulus Summary:
Earthworms benefit soil by leaving behind rich castings, so chemical fertilizers destroying them is enough reason to avoid using them.

Answer Anticipation:
"For this reason alone," is a clear indicator that what follows is supported by the statement that was just highlighted. Since the statement that follows has support, it must be a conclusion—backed up by the word "should," which is much more common in conclusions than premises. The reason given is about the destruction of earthworms, and the last sentence goes into details on why that's such a big deal. Even though that sentence itself features a conclusion ("thus"), it must be subsidiary to the statement that chemical fertilizers should be avoided since the reason behind that statement is that they destroy earthworms—any support for why earthworms are good for soil only supports that main conclusion.

The correct answer, therefore, should reflect that chemical fertilizers shouldn't be used.

Answer Explanation:
This answer reflects the author's opinion and recommendation about chemical fertilizer use, backed up by the benefits of earthworms and the fertilizer's destructive impact on them.

Key Takeaway:
Outside of structural indicator words, there are words and types of statements that tend to be conclusions. "Should" statements fall into that category. Knowing the content words that suggest premise/conclusion can be just as helpful in determining an argument's structure as those structural indicator words—in fact, some conclusions only have one of these indicators and no structural ones.

Incorrect. This is an intermediate conclusion backing up the idea that earthworms are highly beneficial to soil, which itself supports the recommendation against using chemical fertilizers.