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[Reading Comprehension]
试题详情
文章：
| Line | A small number of the forest species of |
| lepidoptera (moths and butterflies, which exist as | |
| caterpillars during most of their life cycle) exhibit | |
| regularly recurring patterns of population growth | |
| (5) | and decline—such fluctuations in population are |
| known as population cycles. Although many different | |
| variables influence population levels, a regular pattern | |
| such as a population cycle seems to imply a | |
| dominant, driving force. Identification of that driving | |
| (10) | force, however, has proved surprisingly elusive |
| despite considerable research. The common | |
| approach of studying causes of population cycles by | |
| measuring the mortality caused by different agents, | |
| such as predatory birds or parasites, has been | |
| (15) | unproductive in the case of lepidoptera. Moreover, |
| population ecologists’ attempts to alter cycles by | |
| changing the caterpillars’ habitat and by reducing | |
| caterpillar populations have not succeeded. In short, | |
| the evidence implies that these insect populations, if | |
| (20) | not self-regulating, may at least be regulated by an |
| agent more intimately connected with the insect than | |
| are predatory birds or parasites. | |
| Recent work suggests that this agent may be a | |
| virus. For many years, viral disease had been reported | |
| (25) | in declining populations of caterpillars, but population |
| ecologists had usually considered viral disease to | |
| have contributed to the decline once it was underway | |
| rather than to have initiated it. The recent work has | |
| been made possible by new techniques of molecular | |
| (30) | biology that allow viral DNA to be detected at low |
| concentrations in the environment. Nuclear | |
| polyhedrosis viruses are hypothesized to be the | |
| driving force behind population cycles in lepidoptera | |
| in part because the viruses themselves follow an | |
| (35) | infectious cycle in which, if protected from direct |
| sun light, they may remain virulent for many years | |
| in the environment, embedded in durable crystals of | |
| polyhedrin protein. Once ingested by a caterpillar, | |
| the crystals dissolve, releasing the virus to infect | |
| (40) | the insect’s cells. Late in the course of the infection, |
| millions of new virus particles are formed and | |
| enclosed in polyhedrin crystals. These crystals | |
| reenter the environment after the insect dies and | |
| decomposes, thus becoming available to infect | |
| (45) | other caterpillars. |
| One of the attractions of this hypothesis is its broad | |
| applicability. Remarkably, despite significant differences | |
| in habitat and behavior, many species of lepidoptera | |
| have population cycles of similar length, between eight | |
| (50) | and eleven years. Nuclear polyhedrosis viral infection is |
| one factor these disparate species share. |
题目：
It can be inferred from the passage that while inside its polyhedrin protein crystals, the nuclear polyhedrosis virus
选项:
A、is exposed to direct sunlight
B、is attractive to predators
C、cannot infect caterpillars’ cells
D、cannot be ingested by caterpillars
E、cannot be detected by new techniques of molecular biology
答案:
C
提问：
这题为什么选c 在文中没有找到对应答案 我选了a
解答：
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阅读973
提问：
这题为什么选c 在文中没有找到对应答案 我选了a
解答：
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阅读974
提问：
找不到在原文哪里定位？谢谢
解答：
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阅读1530
提问：
我选的D，因为第二段接近尾声的地方说“Once ingested by a caterpillar, the crystals dissolve, releasing the virus to infect the insect's cells."说明需要通过”protein crystal"作为介质才能被吞下去。。吞下去nuclear polyhedrosis virus才能感染那个caterpillar。。我是不是读错地方了？ (麻烦老师讲下，换冬令时了，我可能会晚到，实在没到也麻烦老师讲下，谢谢啦！！OUO）
解答：
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阅读1514
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