Self-paced
Support In polluted industrial English cities during the Industrial Revolution, two plant diseases—black spot, which infects roses, and tar spot, which infects sycamore trees—disappeared. ██ ██ ██████ ████ ███ █████████ ██████████ █████ █████████
Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that air pollution most likely eradicated the plant diseases black spot and tar spot. This is based on the observation that those two diseases disappeared in industrial English cities during the Industrial Revolution—places where there was high air pollution.
Notable Assumptions
The author assumes that the observed correlation between air pollution in English cities and the disappearance of the two plant diseases is due to the former causing the latter. This means that the author also assumes there was no alternative cause of the diseases’ disappearance.
4.
Which one of the following, ██ █████ ████ ███████████ ███ █████████ ██████
a
Scientists theorize that ████ ██████ ███ ███████ █ ██████████ ██ ███ ██████████
Like (C), this is irrelevant because we don’t care about plants’ reaction to pollution, only two specific plant diseases.
b
Certain measures help ███████ █████████ ██ █████ ████ ███ ███ █████ ███ ████ █████████ ███████ ██ ██ ████ █████████ ██ ██████████
This is too vague to be useful, because it doesn’t tell us why these diseases are difficult to eliminate or what might succeed in eliminating them.
c
For many plant ████████ ██████████ ████ ███ ██████████ ███ ███████ ██ ███ ██████████
Like (A), this is irrelevant because the author’s hypothesis is about plant diseases, not plants themselves. How plants are affected by air pollution is totally outside the argument’s domain.
d
Black spot and ███ ████ ████████ ████ ███ ███ ██ ███ ██████ ██████ ████ █████████
This strengthens the author’s argument by reinforcing the relationship between air pollution and the two plant diseases. If the diseases come back when pollution decreases, that backs up the hypothesis of a causal relationship.
Plausibility
Plausibility
Presenting evidence that corroborates (in Strengthen) or conflicts (in Weaken) with the author's hypothesized explanation or the predictions that follow from that explanation.
e
Black spot and ███ ████ ████ ███ ████ █████ ████████ ████ ███████████ ██ ███ ███████ ██████ ██████ ███ ██████████ ███████████
This is irrelevant, because we’re only concerned with these two diseases, and this tell us nothing new about them. We simply don’t care about what happened to other plant diseases.