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12、又见sea otter
V1 from ffffighting
变体1. sea otter数量下降,判定原因为killer whales。killer whales捕食seals and sea lions(数量貌似也减少),但很少很少捕食sea otter。问解释
PS:大家考场上一定要小心此题。据考古此题众多变体版本
主人原话:跟qq309790244说得大概一致,但是一下子想不起是问解释还是支持了...
考古 from nowwsy
V1 from qq309790244
kill whale:seaotter数量减少。report说sealion 和seal也下降,killwhale吃sealion和seal,但是报告说killwhale吃seaotter is rare,但在1980前根本没有报告。所以seaotter下降是由于killwhale。问支持
Babee2queen: Sea otter在六月机经里出现过加强的版本:
C)seals and sea lions的食物大量减少,但是sea otters的prey没有减少(正确答案)
e) 在kill whale到不了的bay的sea otters数量和kill whale到的了的数量都减少了。
GWD原题:
In the late 1980’s, the population of sea otters in the North Pacific Ocean began to decline. Of the two plausible explanations for the decline—increased predation by killer whales or disease—disease is the more likely. After all, a concurrent sharp decline in the populations of seals and sea lions was almost certainly caused by a pollution-related disease, which could have spread to sea otters, whereas the population of killer whales did not change noticeably.
Which of the following, if true, most seriously weakens the reasoning?
A.Killer whales in the North Pacific usually prey on seals and sea lions but will, when this food source is scarce, seek out other prey.
B.There is no indication that substantial numbers of sea otters migrated to other locations from the North Pacific in the 1980’s.
C.Along the Pacific coast of North America in the 1980’s, sea otters were absent from many locations where they had been relatively common in former times.
D.Following the decline in the population of the sea otters, there was an increase in the population of sea urchins, which are sea otters’ main food source.
E.The North Pacific populations of seals and sea lions cover a wider geographic area than does the population of sea otters. |
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