Self-study
P1
Discovered in 1993, the site known as Ukhaa Tolgod, in the Gobi desert of Mongolia, is one of the world's best sources of fossils from the Late Cretaceous period, which ended about 65 million years ago. ███ █████████ ███████ ███ ██████ ███████ ████ ████ █████ █████████ ████████ ██████████ ████ ████ █ ███████████ ███████ ███ ███████████████ ████ ██████████ ███
Phenomenon ·
Well preserved fossils
How did they form?
Hypothesis ·
Sandstorm buried the animals
Hypothesis wrong ·
New evidence calls sandstorm hypothesis into question
P2
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Details of Phenomenon ·
Three different types of sandstone at the site
1st Type ·
Well-defined structure
Consistent with sandstorm hypothesis...
2nd Type ·
Tilt and layering
Also consistent with sandstorm hypothesis...
3rd Type ·
No layering; contains large pebbles
Inconsistent with sandstorm hypothesis because the pebbles are too large to have been windblown. This is the type that contains all of the vertebrate skeletal fossils.
P3
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Alternate Hypothesis ·
Sand avalanche caused fossils
Avalanche trapped animals in its path, resulting in the pristine quality of the remains.
P4
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Phenomenon ·
Avalanche / sandslides
What caused them?
Hypothesis ·
Unclear; clay played a role
Unclear but likely clay and rain played a role.
Evidence ·
Modern sand dunes
Implications of hypothesis ·
Sandslide hypothesis suggests area was not sterile desert
Passage Style
Critique or debate
Phenomenon-hypothesis (RC)
22.
Which one of the following ████ ██████████ █████████ ███ ████ █████ ██ ███ ████████
a
Some scientists have ████ ████████ ████ ███ ████ ██████ ███████████ ████████ ████████ ██ ███ █████ ███ ███ ██████████ ██████████ ██ █████ ██████ ███████ ████████ ██ ███████ ████ ███████
This doesn’t capture the author’s believe that sandslides, not sandstorms, may explain why the fossils are so well-preserved.
b
Though the causes ██ ████████████ ██████████ ██ █████ ███ ███ ████████ ███████████ ██████████ ████ ███ ███████ ██ █ ██████████ ███████████ ███ ███ ██████████ ████ ████████ ██ █████ ███████
Not supported, because the author never suggests that scientists have “settled” on an explanation for how sandslides occurred at Ukhaa Tolgod. It’s not even an established fact that sandslides occurred at this location. The author proposes evidence that sandslides occurred, but it’s not an established fact that anyone has a settled view about. Since (B) isn’t supported, it can’t be the main point.
c
Investigations of geological ██████████ ██ █████ ██████ ████ ██████ ███ ███████████ █████ ████████ ██ ████████ ████████████ ███ ████ ██████ ███ ████ █ ██████ ████ ██████
This doesn’t capture the author’s believe that sandslides, not sandstorms, may explain why the fossils are so well-preserved. Although it’s true that the author believes Ukhaa Tolgod may have been a stable dune field, the point isn’t to establish this possibility. It’s to explain why the fossils at Ukhaa Tolgod are so well preserved.
d
Geological evidence suggests ████ ███ ███████ █████ ██████████ █████████ ████ ████ █████ ██ █████ ██████ ████ ████ ████████████ ██████████ ██████ ████ ████ ███████████
This best captures the author’s main point, which is that there’s evidence sandslides, not sandstorms, preserved the fossils at Ukhaa Tolgod. The author suggests that animals died from sandslides, which helped preserve their fossils. The author advances this hypothesis in P2, P3 and P4, after discussing evidence against the sandstorm hypothesis in P2. Let’s look for an answer that capture the hypothesis the author advocates.
e
The search for ██████████ █████████ ███████ ███ ██████ █████████ ██ █████ ██████ ███ ████████ ██████████ ████ ███ ████████ ██████████ ███ ████ ██ █████ ███████ █████ ██ █████████ ███ ███████
This doesn’t capture the author’s believe that sandslides, not sandstorms, may explain why the fossils are so well-preserved.