阅读理解 For most species of animals, the number of individuals in the species is inversely proportional to the average body size for members of the species: the smaller the body size, the larger the number of individual animals. The tamarin, a small South American monkey, breaks this rule. Of the ten primate species studied in Peru's Manu National Park, for example, the two species of tamarins, saddle-backed and emperor, are the eighth and ninth least abundant, respectively. Only the pygmy marmoset, which is even smaller, is less abundant. The tamarin's scarcity is not easily explained; it cannot be dismissed as a consequence of diet, because tamarins feed on the same mixture of fruit, nectar, and small prey as do several of their more numerous larger counterparts, including the two capuchins known as the squirrel monkey and the night monkey. Although the relative proportions of fruits consumed varies somewhat among species, it is hard to imagine that such subtle differences are crucial to understanding the relative rarity of tamarins.
To emphasize just how anomalously rare tamarins are, we can compare them to the other omnivorous primates in the community. In terms of numbers of individuals per square kilometer, they rank well below the two capuchins, the squirrel monkey and the night monkey. And in terms of biomass, or the total weight of the individuals that occupy a unit area of habitat, each tamarin species is present at only one-twentieth the mass of brown capuchins or one-tenth that of squirrel monkeys. To gain another perspective, consider the spatial requirements of tamarins. Tamarins are rigidly territorial, vigorously expelling any intruders that may stray within the sharply defined boundaries of their domains. Groups invest an appreciable part of their time and energy in patrolling their territorial boundaries, announcing their presence to their neighbors with shrill, sweeping cries. Such concerted territoriality is rather exceptional among primates, though the gibbons and siamangs of Asia show it, as do a few other New World species such as the titi and night monkeys. What is most surprising about tamarin territories is their size.
Titi monkeys routinely live within territories of 6 to 8 hectares, and night monkeys seldom defend more than 10 hectares, but tamarin groups routinely occupy areas of 30 to 120 hectares. Contrast this with the 1 to 2 hectares needed by the common North American gray squirrel, a nonterritorial mammal of about the same size. A group of tamarins uses about as much space as a troop of brown capuchins, though the latter weighs 15 times as much. Thus, in addition to being rare, tamarins require an amount of space that seems completely out of proportion to their size.

单选题 8.The author indicates that tamarin territories are

【正确答案】 A

【答案解析】Supporting idea
This question depends on understanding what the passage says about tamarin territories. In the second paragraph, the passage claims that the most surprising thing about tamarins is the size of their territories, and it indicates how large these territories are by comparing them to the territories of certain other animals.
A Correct. The passage indicates that the size of tamarins'territories—large in comparison to the territories of several other species—is surprising.
B The passage gives no indication as to whether tamarin territories are poorly situated.
C Although the passage does discuss the tamarin diet, it does not indicate how abundant in food sources tamarin territories are.
D The passage does indicate that relatively few tamarins live per square kilometer, but it does not claim that this is so because the territories are incapable of supporting a larger number of tamarins. In fact, there is some suggestion that the territories would seem to be capable of supporting more, which is one reason the size of the territories is so surprising.
E The passage does not compare the size of tamarin territories in Peru to tamarin territories elsewhere in South America.
The correct answer is A.

单选题 9.The author mentions the spatial requirements of the gray squirrel in order to

【正确答案】 C

【答案解析】Evaluation
The passage mentions the spatial requirements of the gray squirrel as part of its discussion of the surprising size of tamarin territories. Gray squirrel territories are mentioned for the specific purpose of highlighting how much more space tamarins require compared to another animal of roughly equal size.
A The passage does refer to "the common gray squirrel," but it does not explain why they are so common.
B The passage does not say anything about the consequences of the gray squirrel's nonterritoriality.
C Correct. The spatial requirements of gray squirrels are mentioned to highlight, by contrast, how expansive the spatial requirements of tamarins are.
D Although the passage mentions the spatial requirements of the gray squirrel to highlight how different the spatial requirements of one particular type of monkey, the tamarin, are from those of other animals, the passage does not mention the squirrels' spatial requirements to provide an example of a difference between squirrels and monkeys in general.
E The passage actually does the opposite of this—it mentions the gray squirrel's spatial requirements to provide an example of an animal with requirements vastly different from those of the tamarin.
The correct answer is C.

单选题 10.The author regards the differences between the diets of the tamarins and several larger species as

【正确答案】 B

【答案解析】Supporting Idea
This question depends on recognizing that the passage rejects the idea that any differences between the diets of tamarins and those of certain larger animals are large enough to explain tamarins' relative rarity. The passage points out that these animals feed on the same fruits, nectar, and small prey, and claims that though the proportions of the fruits consumed varies somewhat, this variation is not sufficient to explain the tamarins rarity.
A The author does not seek to explain why these differences in diet—which the passage indicates are minimal—exist. Given that the author indicates that differences in territory size are large and differences in diet are small, it is unlikely, in any case, that the author would regard the former as explaining the latter.
B Correct. The passage indicates that the differences in diet among these animals are too small to explain the rarity of tamarins.
C The author does not give any indication that the differences in the diets of these animals are predictable based on differences in body size.
D The author does indicate that tamarins are rather unusual among primates in their rigid territoriality, but there is no indication that this rigid territoriality explains the small differences in diet among tamarins and certain larger animals.
E The author mentions differences in diet merely to rule out that these differences are large enough to explain tamarins' rarity; these differences are not mentioned as a factor in determining behavioral differences.
The correct answer is B.

单选题 11.Which of the following would most probably be regarded by the author as anomalous?

【正确答案】 E

【答案解析】Application
This question requires you to understand an underlying principle of the passage and to apply that principle to an instance that is not specifically discussed in the passage. The passage is concerned with how anomalous tamarins are: they are exceptions to the general rule that in general the number of animals in a species is proportional to the average body size of individuals within the species. The author also points out that tamarins are unusual in that the amount of space they require is out of proportion to their body size, suggesting the principle that an animal's spatial requirement is generally proportional to the animal's body size. And, though the passage is generally concerned with comparing tamarins to other primates, the author also compares tamarins' spatial requirements to those of gray squirrels, a type of rodent.
A The author does not give any indication whether it would be anomalous for a species of large primates to eat mostly plants. The author does not present a general principle about the diets of primates, and says nothing specific about species of large primates.
B Although the author indicates that the "rigid" territoriality of tamarins is "rather exceptional among primates," the author lists several other primate species that are also territorial. The author does not indicate whether such territoriality is rare among small mammals in general.
C The author indicates that most primates do not have "such concerted territoriality" as tamarins do, suggesting that the author may not think that two other species of small primates sharing territories would be anomalous.
D Given that the author indicates that generally the number of individuals within a species is inversely proportional to the average body size of the members of the species, the author would probably expect that a species of small birds would be more abundant than most species of larger birds and would not regard this as anomalous
E Correct. The author would generally expect that smaller animals would require less living space than larger animals.
The correct answer is E.

单选题 12.The author most probably regards the tamarins studied in Manu National Park as

【正确答案】 B

【答案解析】Inference
This question requires you to make an inference from what the author says about the tamarins studied in Manu National Park to a claim about how the author most likely regards these tamarins. The author considers certain information that has been gathered about the two tamarin species studied in the park, and on the basis of that, makes claims about tamarins in general (note that the author elsewhere in the passage simply refers to "tamarins" without qualification, i.e., without referring specifically to "the tamarins studied in Manu National Park''). This suggests that the author would regard the tamarins studied in the park as being typical of tamarins generally, at least in the ways discussed.
A It is possible that the two tamarin species studied in the park are endangered, but apart from noting the surprisingly small number of individuals belonging to the species, there is no information that would suggest that they are endangered, and the mere fact that the number of members is relatively small compared to the number of members in other species is not sufficient to indicate that they are endangered, as that number could nonetheless be stable or even growing.
B Correct. The author does not specifically mention anything that would indicate that these tamarins are atypical of tamarins in general, and appears to make inferences about tamarins in general on the basis of the two species studied in the park. The author would not be justified in making such inferences if the author believed that the tamarins observed in the park were not in fact typical.
C The author does not give any indication that these species are unusually docile, and in fact suggests the opposite by indicating that tamarins vigorously expel any intruders from their territories.
D The author does note some ways in which these tamarin species are unusual among primates, but does not indicate that they are "the most unusual primates anywhere."The author, in fact, indicates that in one of the ways that these species are unusual—their relative scarcity despite their small body size—another primate species, the pygmy marmoset, is even more unusual.
E Because the author appears to make some inferences from information about the tamarins studied in the park to claims about tamarins in general, the author does not seem to regard the tamarins studied in the park as too small a sample to be significant.
The correct answer is B.

单选题 13.Which of the following is NOT mentioned in the passage as a species whose groups display territoriality?

【正确答案】 D

【答案解析】Inference
This question requires you, by process of elimination, to identify the species that is NOT explicitly mentioned as being a species displaying territoriality. Each of the species given in the answer choices is explicitly mentioned in the passage, and all but one of these species are explicitly described as displaying territoriality. In lines 38-41, the author states, "concerted territoriality [like that of tamarins] is rather exceptional among primates, though the gibbons and siamangs of Asia show it, as do a few other New World species such as the titi and night monkeys." So, clearly, gibbons, siamangs, titi monkeys, and night monkeys are each said to display territoriality. Squirrel monkeys, the remaining answer choice, are mentioned three different times in the passage (see lines 16,25, 30), but never as displaying territoriality.
A Gibbons are identified as displaying "concerted territoriality" (line 39).
B Siamangs are identified as displaying "concerted territoriality" (line 39).
C Titi monkeys are identified as displaying "concerted territoriality" (line 41).
D Correct. Although squirrel monkeys are mentioned three times in the passage (lines 16,25, and 30), in none of the instances are they mentioned as displaying territoriality.
E Night monkeys are identified as displaying "concerted territoriality" (line 41).
The correct answer is D.

单选题 14.The primary concern of the passage is to

【正确答案】 C

【答案解析】Main idea
Answering this question requires identifying an abstract description of the primary purpose of the passage. The passage focuses in different ways on an unusual condition, namely, the anomalous relationship between tamarins' relatively small average body size and the number of individuals in the species.
A The passage is not concerned with recommending any policy.
B The passage does not focus on any theory; it considers a phenomenon, but proposes no theory to explain that phenomenon.
C Correct. The passage's primary concern is to describe an unusual phenomenon, namely, how tamarins "break the rule" that, in general, the number of individuals in a species is inversely proportional to the average body size of members of the species.
D The passage is primarily concerned with a particular, unusual phenomenon, but it offers no hypothesis regarding it, nor does it discuss the development of any such hypothesis.
E Although the passage gives passing consideration to some hypotheses, its primary concern is to note certain characteristics of tamarins. The passage does not primarily concern itself with any hypotheses.
The correct answer is C.