PT156 S1 P4 Q22 ExplanationSand Fossils

Answer choices, explained

1. A

   Wrong Emphasis: missing 'fossils'1% picked this

   Some scientists have long believed that the Gobi desert experienced abundant rainfall in the past, and the geological formations at Ukhaa Tolgod

   This answer doesn't reference the fossils we're trying to explain, so we should get rid of it without reading too deeply. The "geological formations" at Ukhaa Tolgod refers to the various types of sandstones, not the fossils. The OLD belief in this answer is that "the Gobi desert experienced lots of rainfall back in the past", whereas the OLD belief in the passage is that "the fossils were trapped by a sudden, violent sandstorm". This answer is doing the Last Sentence Trap, where it regurgitates something we were told about in the last sentence, since they know that sentence is still ringing in our ears.

   1%
2. B

   Wrong Emphasis6% picked this

   Though the causes of rain-induced sandslides in dunes are not entirely understood, scientists have now settled on a particular explanation for the

   Wrong Emphasis: missing 'fossils' Too Strong: settled on This answer doesn't reference the fossils we're trying to explain, so we should get rid of it without reading too deeply. Were we to read more closely, we wouldn't be able to sign off on the idea that "scientists have now settled on a particular explanation for sandslides" as a main point or even a supported claim.

   6%
3. C

   Wrong Emphasis: missing 'fossils'22% picked this

   Investigations of geological formations at Ukhaa Tolgod have raised the possibility that, contrary to previous assumptions, the Gobi desert was

   This answer doesn't reference the fossils we're trying to explain, so we should get rid of it without reading too deeply. This answer, to its credit, does say something true, although it's not clear that the takeaway in the final sentence runs "contrary to previous assumptions". But the main point wasn't, "we think the Gobi desert was once a stable dune field". The main point was, "We're now thinking that these fossils weren't preserved by sandstorms, but rather by sandslides."

   22%
4. D

   Correct67% picked this

   Geological evidence suggests that the animals whose fossilized skeletons have been found at Ukhaa Tolgod died from rain-induced

   Why this is right

   This is the only answer choice that even mentions the central topic, which is this exceptional repository of fossils found at Ukhaa Tolgod. This conveys the fact that the passage was rejecting a previous explanation (sandstorms) and proposing a new tentative explanation (sandslides).

   Skill tested: Main Point · how this choice captures the passage's function is the move to repeat next time.

   67%
5. E

   Wrong Emphasis: missing 'fossils'4% picked this

   The search for fossilized dinosaur, lizard, and mammal skeletons at Ukhaa Tolgod has provided scientists with new evidence concerning the ways in which

   This answer at first seems like it's talking about the extraordinary repository of fossils that is the central topic of the passage, but it's not. It's talking about the search for new fossils. The passage isn't about that at all. We're just trying to figure out how these fossils we've already found are in such good condition. Our previous theory was sandstorms, but now we're thinking sandslides, neither of which are mentioned in this answer.

   4%