#23 - Must Be True

[Administrator]

Complete Question Explanation
(See the complete passage discussion here: lsat/viewtopic.php?t=14217)

The correct answer choice is (D)

This question asks what is most likely to be true of soil used to replace the overfarmed soil discussed
in the first paragraph.

Answer choice (A): Nothing in the passage suggests that replacement topsoil would be immune to
thistles, so this choice fails the Fact Test and should be ruled out of contention.

Answer choice (B): Replacement topsoil might contain fungi; the passage does not suggest
otherwise.

Answer choice (C): The passage suggests that soil containing seeds of native grasses and seeds
would be better able to fight off thistles and other aggressive weed species, so there would be no
reason to conclude that replacement topsoil would have few such seeds.

Answer choice (D): This is the correct answer choice. Replacement topsoil would not likely
contain large amounts of fertilizer, since the presence of fertilizer is one of the problems specified to
be an issue with such over-farmed land.

Answer choice (E): The passage does not suggest that replacement topsoil has never before been
used for growing commercial crops, so this choice is unsupported and cannot be the right answer to
this Must Be True question.

[alee]

Hi,

Firstly, thanks Nikki + Adam for the awesome help with PT 66. This question is about the 4th passage in PT 65, Section 3, Q 23.

Why is it that the following is correct?:

D: It does not contain large amounts of fertiliser.

Is it that: from the discussion of soil replacing topsoil in heavily fertilised soil, since the problem originates from the the soil being heavily fertilised, we can infer that the soil that's replacing this *in order to solve the problem* won't be heavily fertilised.

Also, can I ask if you could recommend a few science passages in this style? I've done the ones in the RC bible, so perhaps if you could recommend some other good ones?

Cheers!

[Adam Tyson]

Alee,

Your analysis of answer choice D is right on - the inference to be drawn here is that we are replacing heavily fertilized soil with soil that is less fertilized, if at all.

I don't have any specific recommendations for passages for you to practice, but I do recommend finding articles in a variety of non-LSAT sources just to practice your reading and LSAT analysis skills on. Hit the library or bookstore and grab copies of journals on farming, gardening, medicine, physics, engineering, psychology, etc. and read them with n eye towards identifying main points, attitudes, inferences to be drawn, structure, etc.

Hope that helps. Good luck!

Adam

[pmuffley]

Hello! I'm not quite understanding why C is incorrect. If they have to sow the seeds into the plots, then wouldn't it make sense that the topsoil they are putting in "contains very few seeds of native grasses and herbs"? In the second paragraph, it says, "The remaining plots were divided into two groups: plots in one group were sown with a mixture of native grasses and herbs; those in the other group received the same mixture of grasses and herbs together with clover and toadflax".

Why would they have to sow in these things if the topsoil already had these things?

I was between C and D, but I picked C because, and this may seem stupid, but I felt like D was too obvious and C was implied. I thought they were trying to pull a shell game on me

[Adam Tyson]

You might be confusing two different things being discussed in the passage, pmuffley, and the authors are counting on you to do that! The question is asking about the replacement soil described in the first paragraph. That's pointing you back to this:

the quickest way to restore heavily fertilized land is to remove and replace the topsoil

This replacement soil is NOT the soil discussed later in the passage! The rest of the passage is about the process being used in the Netherlands, where it was impractical to just replace the old topsoil with new stuff and they had to rake out the old soil and seed it with different things to restore it to a natural state. The replacement option in the first paragraph, when practical, would be easier because you wouldn't have to do all that restorative work! You just take away the old stuff and put in new stuff that has none of the problems of the old stuff, including that it doesn't have all the fertilizer that helped those pesky thistles to proliferate!

We can't say whether the new soil would have the native seeds in it or not. It might! That might be part of what makes it a good, easy option in some cases. We just know that it won't have the problems found in the old soil, like fertilizer and thistles and depleted nutrients.

One last thing, and that is about your decision to reject the "obvious" answer and go for one that seemed more subtly implied: never do that! "Too obvious" might be a reason to give an answer a second look, just in case it's a trap, but it's never, ever a good reason to reject an answer. Sometimes the answers are obvious because they are right and because you know what you are doing and are good at this stuff! It's okay to suspect that an "obvious" answer might have a problem and be a trap, but reject an answer only because it is clearly incorrect, or because another answer is clearly superior.