Self-study
Geologist: As a spinning object's radius decreases, its rate of rotation increases; for example, figure skaters can twirl faster by bringing their arms closer to their sides. ████ ███ ██ ███████ █████ ██ ███████ ████ ████ ███ ████ ███████ ███████ ████ ██ ████████ ██████████ ███ ███████████ ████ █████████ ██ ██████ ███ ████████ ██████ ███ ████ ███████ ███ █████ ███████████ █████ ██ ██████████ ███████ ████████ ██████ ████ ██████ ███ ██████ ██ ███ ██████ █████ ████████ ██████ ███████ ██████ ██ █████████
Summarize Argument: Phenomenon-Hypothesis
A Geologist believes that Earth’s rate of rotation increased over the past decade due to a law of physics: as a spinning object’s radius decreases, its rate of rotation increases. The Geologist claims that the increase in the number and severity of earthquakes have caused the Earth’s tectonic plates to move toward the center of the Earth, causing the radius to decrease and the speed to subsequently increase.
Notable Assumptions
The author assumes that the movement of tectonic plates toward the center of the Earth outweighs any other factors that could cause the Earth’s radius to increase.
19.
Which one of the following, ██ █████ █████ ████ █████████ ███ ███████████ ███████████ ██ ███ ███████ ████ ██ ████████ █████████ ████ ███ ████ ███████
a
In the beginning ██ ███ █████████ ████████ ██████████ ████████ ██ ████████ ██ ██████ ███ ████████ ██ ████████████ ███████████ ██ █ ████████ ██ ███████ ███████
This supports the argument by bolstering the idea that earthquakes are causing the Earth’s radius to decrease.
b
During the past ███████ █████ ██████████ ██████ ████ ████████████ ███ █████████ ██ ███ ████████ ██████ ████ █████ ███████████ █████ ████████████
This undermines one of the geologists' key assumptions: that another force did not counteract the decrease in the Earth’s radius from earthquakes. If this is true, the entire support of the argument is weakened, and its conclusion is called into question.
c
Only skillful figure ███████ ███████ ██ ████████ ██████ ██ ████████ █████ ████ ██████ ██ █████ ██████
This is completely unrelated to the argument. The info about the skater is just context to explain how the law of physics works.
d
Since the time ██ ███ ███████ ██████████ ███████ ████ ██ ████████ ███ ████ █████ ██ ██████████
If anything, this strengthens the argument by giving credence to the idea that the Earth’s rate of rotation changes. But it certainly gives nothing to weaken the argument.
e
Increased volcanic activity ████ ███ ████ ███ █████ ████████ ████ ███ ███████ ████████ ██ ███ ████████ ██████ ███ ██████████
This does not say whether the tectonic plates are moving inward or outward. If anything, it is easiest to assume that the tectonic plates are moving inward, which would strengthen the argument, not weaken it.