Self-study
Paleontologists had long supposed that the dinosaur . ██████████ ███████ ███ ████████████ ██████████ ████ ██ ███████ ██████ ██ ███████ ███ ████ ████ █████ ███ ███ ████████ ██████ ████ █████ ████ ███ █████████ ██ ████████████ ████ █████ █████ ████ █████████ ████ █████████ ███ ████ ██████ ████████ ████ ████████ ███ ████ ██████ █████ ██████ ██████ ████████ ██████████ ██ ██████ ██████████ ██████████ ████ ███ █████ █████ ██████████ ████ ████ ███ ██ ██████ ██ ██ ████ ███ ███████ ██ ███████████
Summary
The author concludes that Diplodocus must have fed on plants on or near the ground, or underwater.
What makes the author think this?
The structure of Diplodocus’s neck bones didn’t allow it to raise its long neck in the air to eat high-growing vegetation.
But its neck could bend downward and extend below ground level, which allowed access to underwater vegetation from dry land.
Notable Assumptions
The author assumes there’s no other way Diplodocus could have eaten high-growing vegetation besides raising its long neck in the air.
The author assumes that Diplodocus did not eat solely meat or other types of food besides plants.
4.
Which one of the following ██ ██ ██████████ ████████ ██ ███ █████████
a
The same type ██ ████ █████████ ██ █████ ██ ██████ ██████████████ ████████
Not necessary, because the author’s argument does not rely on any claims about modern ground-feeding animals. Even if the same type of neck structure is NOT found on modern ground-feeding animals, those animals could simply have different body features that allow them to eat ground-level food.
b
Diplodocus was not ████ ██ ███ ██ █████ ██ ██████ ██████ ███ ████ ███ ██████ ███████ █████████
Not necessary, because the argument doesn’t depend on any claims about what Diplodocus was able to see.
c
It would be ██████████ ███ █ █████ ██████ ████ ██ ██████████ ██ ██████ █████ ██ ██ ████████ ██████
Not necessary, because even if it’s possible for a large animal like Diplodocus to supply blood to an elevated brain, the reason given for why the Diplodocus didn’t feed on high-growing vegetation has nothing to do with inability to supply blood to the brain. The reason is based on the structure of the animal’s neck bones.
d
Diplodocus had no █████ ███ ██ █████████ ████████████ ███████████ ████ ██ ██ ██████ ██ ██ ███ ████ █████
Necessary, because if it were not true — if Diplodocus DID have other ways of accessing high-growing vegetation, such as by rising up on its hind legs — then the fact the animal’s neck couldn’t raise into the air wouldn’t prove that Diplodocus didn’t feed on high-growing vegetation. The negation of (D) would raise the possibility Diplodocus could have fed on high-growing vegetation.
e
Diplodocus was not ████ ██ ██████ ███ ██████████ ██████████ ██ ████████ ██████ ██████ ██ █████ ██ ██ ███████ ████ █████
Not necessary, because the negation of (E) actually helps the argument. If the Diplodocus COULD browse underwater vegetation by kneeling besides water, that provides another reason to believe it may have fed on plants underwater.