GMAT考试资料：GWD试题合集（三十三）.

　　以下将为正在备战GMAT考试的同学们整理一些经典的GMAT阅读试题，并分多个合集推出，希望能够为正在备考GMAT考试的考生提供或多或少的帮助。

　　16. GWD-13-Q34 -Q37是谁控制着毛毛虫的生命长度

　　A small number of the forest

　　species of lepidoptera (moths and

　　butterflies, which exist as caterpillars

　　Line during most of their life cycle) exhibit

　　(5) regularly recurring patterns of popu-

　　lation growth and decline—such

　　fluctuations in population are known

　　as population cycles. Although many

　　different variables influence popula-

　　(10) tion levels, a regular pattern such as

　　a population cycle seems to imply a

　　dominant, driving force. Identification

　　of that driving force, however, has

　　proved surprisingly elusive despite

　　(15) considerable research. The com-

　　mon approach of studying causes of

　　population cycles by measuring the

　　mortality caused by different agents,

　　such as predatory birds or parasites,

　　(20) has been unproductive in the case of

　　lepidoptera. Moreover, population

　　ecologists’ attempts to alter cycles

　　by changing the caterpillars’ habitat

　　and by reducing caterpillar popula-

　　(25) tions have not succeeded. In short,

　　the evidence implies that these insect

　　populations, if not self-regulating, may

　　at least be regulated by an agent more

　　intimately connected with the insect than

　　(30) are predatory birds or parasites.老观点及其方法

　　Recent work suggests that this

　　agent may be a virus. For many

　　years, viral disease had been

　　reported in declining populations

　　(35) of caterpillars, but population ecolo-

　　gists had usually considered viral

　　disease to have contributed to the

　　decline once it was underway rather

　　than to have initiated it. The recent

　　(40) work has been made possible by

　　new techniques of molecular biology

　　that allow viral DNA to be detected

　　at low concentrations in the environ-

　　ment. Nuclear polyhedrosis viruses

　　(45) are hypothesized to be the driving

　　force behind population cycles in

　　lepidoptera in part because the

　　viruses themselves follow an infec-

　　tious cycle in which, if protected from

　　(50) direct sun light, they may remain

　　virulent for many years in the envi-

　　ronment, embedded in durable

　　crystals of polyhedrin protein.

　　Once ingested by a caterpillar,

　　(55) the crystals dissolve, releasing

　　the virus to infect the insect’s cells.

　　Late in the course of the infection,

　　millions of new virus particles are

　　formed and enclosed in polyhedrin

　　(60) crystals. These crystals reenter the

　　environment after the insect dies and

　　decomposes, thus becoming avail-

　　able to infect other caterpillars.新观点及其论据

　　One of the attractions of this

　　(65) hypothesis is its broad applicability.

　　Remarkably, despite significant differ-

　　ences in habitat and behavior, many

　　species of lepidoptera have population

　　cycles of similar length, between eight

　　(70) and eleven years. Nuclear polyhe-

　　drosis viral infection is one factor these

　　disparate species share.新观点正评价

　　老新观点

　　1P: population cycle, identify driving force, however, surprising elusive. Common approach unproductive; ecologist’s attempt, not succeed. In short, population regulated by intimated connected with insects.

　　2P: recent work suggest virus. Contributed to. Recent work made possible by new techniques. NP hypothesized because…

　　3P: attractions of hypothesis is ….

　　以上就是本期GMAT试题的所有内容，考生可以此为据并进行针对性的练习，逐步掌握GMAT阅读的解题规律及技巧，以达到迅速提高GMAT考试成绩的目的。 相关链接：

1.GMAT考试资料：GWD试题合集（三十二）

2.GMAT考试资料：GWD试题合集（三十一）

3.GMAT考试资料：GWD试题合集（三十）

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