PrepTest 110, Section 3, Question 6
Standard archaeological techniques make it possible to determine(68 more words not shown)
Which one of the following,(7 more words not shown)
- AThere exist several(10 more words not shown)
- BLaboratory procedures exist(14 more words not shown)
- CThe age of(13 more words not shown)
- DPrehistoric artists did(11 more words not shown)
- EThe proportion of(14 more words not shown)
Reading the argument
Why can't we separate the paint from the limestone after we collect it?
I understand the obstacle at the wall. When we scrape off some paint, limestone comes off with it. The limestone contains carbon, and the passage tells us that this prevents the standard techniques from dating the vegetable matter in the paint. Let's accept that restriction.
But collecting the sample and testing the sample are different steps. We could bring a mixture back to the lab, remove the limestone there, and then test the paint. The argument tells us the two materials have to come off together. It never establishes that they have to stay together.
What we’re looking for
That's my prediction for the weakener: a way to separate the materials before testing. We wouldn't need a new dating technique or a way to collect pure paint directly from the wall. We would just need to remove the obstacle to using the existing technique.
Working the answers
- A
Several ways to collect a sample don't help if all of them collect limestone along with the paint. We already know that collecting the paint without limestone is impossible. A doesn't say any of these methods removes the limestone afterward, so the barrier to dating remains.
- BCorrect
We can remove all the limestone in the lab. That allows the sample to start out mixed, just as the passage says, and still end up suitable for dating. Once the limestone is removed, its carbon no longer prevents the standard technique from being used on the vegetable matter. B directly answers the concern that made us question the conclusion.
- C
Dating the rock isn't the same as dating the painting. The limestone could have existed long before an artist put paint on it. We want to know the age of the paint, and C doesn't give us that or remove the limestone from a paint sample.
- D
The problem is the limestone mixed into the sample, not some extra ingredient in the original paint. Even if the artist used only vegetable matter, collecting that paint still brings limestone with it. D does nothing to separate the two before testing.
- E
Knowing the proportion of carbon in limestone doesn't establish that we can date paint mixed with limestone. We'd have to add an unstated claim that this knowledge lets us get around the restriction. B actually removes the contaminating material; E merely describes it.
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