Self-study
The giant Chicxulub crater in Mexico provides indisputable evidence that a huge asteroid, about six miles across, struck Earth around the time many of the last dinosaur species were becoming extinct. ███ ████ ███████████ ███ ████████ ███ ███████████ ███ ████ ██ █████ ████████████ ███ █████ ████████ ██████ █████ ████ █████████ ██ ██ ████ ███ ██████ ██ ███ ███████ ███ █████ ██ ██████ ████████ ████ ████ █ ██████ █████ ████ █ █████████ ███████ ███████ ████ ███████ ████ ██████ ████ ███ █████████ ██████ ████ ████ ██████ █████ ██ ███████ ███████ ████ █████ ████ ██ █████ ████████████
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that the Chicxulub asteroid strike wasn’t responsible for most dinosaurs going extinct. Why? Because even a major asteroid strike doesn’t have worldwide consequences. What's more, there are even larger asteroid craters out there, from strikes that were accompanied by no known extinctions whatsoever.
The author is making a phenomenon-hypothesis argument, saying that a particular hypothesis (that the Chicxulub asteroid didn't wipe out the dinosaurs) best explains observed phenomena (the extinction, but also what we know about asteroid impacts). To weaken, we can look for an alternative explanation. We can also search for overlooked considerations in order to attack the author's assumptions.
Notable Assumptions
The author's hypothesis is supported with a claim about the low potential for worldwide impact from an asteroid strike, and an analogy to other major asteroid strikes. Both of these require assuming something about the Chicxulub strike, and we can weaken by attacking those assumptions.
For the limited worldwide impact of an asteroid strike to be relevant, the author must assume that the dinosaur population was distributed worldwide. If dinosaurs were all concentrated near Chicxulub, a local impact could be sufficient to wipe them out.
For other asteroid strikes to provide useful evidence, they must have been relevantly similar to the Chicxulub strike. In other words, the author assumes that there was nothing meaningfully distinct about the Chicxulub asteroid, or the conditions at the time it struck.
8.
Which one of the following, ██ █████ █████ ████ ██████ ███ █████████
a
The vast majority ██ ████████ ███████ ███ █████ ██ ████ ████ ███████ ████ ██████ ███ ████ ██ ███ ████████ ██████ ████ ████████ ███ █████████ ███████
The author's hypothesis is about whether the asteroid caused the extinctions that happened around the time of the strike. Whether there were many or few dinosaur species left at the time just isn't relevant, so this can't weaken.
b
The size of █ ██████ ██████ ██ ██ ████████ ████████ █████ █████████ ███████ ██ ████ ███ ████ ██ ████ ████████ ███ ███ █████ ██ ███ ███████
We're not aware of any reason why the relative size or force of an asteroid would make a difference to its extinction-causing potential. This also doesn't actually tell us if the Chicxulub asteroid was especially large or forceful. This doesn't give us enough information to weaken.
c
Fossils have been ██████████ ██ █ ██████ ██ █████████ ████ ███████ ████ ██ █ ██████ ██ ███ ████████ ██████ ████ ████████ ███ █████████ ███████
The fact that the asteroid killed some dinosaurs doesn't undermine the author's hypothesis that it didn't cause most of the extinctions at the time. Killing some dinosaurs doesn't equate to even one extinction, let alone many.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion.
d
There is no ████████ ████ ███ █████ ████████ ██ █████ ████ ██████ █████ ██ ███ ████ ████ ██ ███ ████████ ████ ████████ ███ █████████ ███████
If anything, this strengthens the author’s argument by pointing out that the Chicxulub asteroid wasn’t part of some larger asteroid event. This partially affirms the assumption that the Chicxulub asteroid was comparable to any other asteroid of a similar size.
e
During the period ███████████ ██████ ███ ████████ ████ ████████ ███ █████████ ██████ ███████ ████ ██ ███ ███████ █████████ █████ ██ ██ ████ ███ ██████ ██ ███ ██████████ █████████ ███████
This undermines the assumption that the dinosaur population was distributed worldwide. If dinosaurs were all concentrated near Chicxulub, it's much more plausible that the asteroid strike wiped them out, even without a global impact. This effectively weakens.