transformation of the river in Grand Canyon, so the correct answer should match this
information. Choice (A) is a good fit, so keep it. Eliminate (B), as no mention is made of
casual observation, as well as (C) because the passage never hints at collaboration
between scientists and the public. Choice (D) is too extreme because the passage never
proves anything. Choice (A) is correct.
C The first paragraph of Passage 1 discusses the humpback chub and mentions that it has been
listed as endangered, as well as that the dam and its operation jeopardized the continued
existence of humpback chub in Grand Canyon. Choice (A) is incorrect because it’s too
extreme. The chub is endangered, not extinct. Choice (B) refers to the fish later in the
passage instead of the chub, so eliminate it. Choice (D) is never mentioned, so eliminate
this choice as well. This leaves (C), which is correct; it can be inferred the chub can
survive a variety of environments because it’s still alive.
C Go to the first sentence of the second paragraph in Passage 1 and cross out the word
regime. Replace it with your own word using the context of the paragraph. A good
replacement would be “process,” so find a word in the answer choices that matches this
meaning. Choice (C) fits, so keep it for now. Choice (A) is a dictionary definition of
regime, so eliminate it. Choices (B) and (D) are not related to “process” in any way, so get
rid of them as well. Choice (C) is therefore correct.
B Go to the second sentence of the second paragraph in Passage 2 and cross out the word
suspended. Replace it with your own word using the context of the paragraph. The
paragraph mentions that sand is included at high concentration in the flow, so a good
replacement would be “combined.” Choice (B) is the best match and therefore the correct
answer.
C Use POE to find an answer consistent with the passage. Controlled floods are discussed in
the final two paragraphs, so this should be the reference window. Choices (A) and (D) are
incorrect because snowmelt is mentioned only in the first passage. While controlled floods
sometimes lead to the higher concentrations of suspended sand, this is not always the case.
Therefore, (B) can be eliminated. Choice (C) works because the first sentence of the final
paragraph states that the floods may erode sandbars if the concentration of suspended
sand during a controlled flood is too low. Therefore, (C) is correct.
D The correct answer to the previous question deals with the negative effects of controlled
flooding on the health of the river, so the answer to this question should reflect this theme.
The lines referenced in (D) describe sandbar erosion, which would certainly qualify as
something “detrimental”; therefore, (D) is the correct answer. The lines from the passage
referenced by the other answer choices do not illustrate any negative effects on the river.
A The High Flow Experiments mentioned in Passage 2 refer to controlled floods used to
increase sandbars. Therefore, the author of Passage 1 would have a positive attitude
towards these floods because Sandbars, riverbanks, and their accompanying aquatic
habitats were reshaped, which is ultimately beneficial to the ecosystem. Choice (A) is a
good match for this information. Eliminate (B), (C), and (D) because they are too negative.