GWD 24-6

juliaPL

24-Passage one

    More selective than most chemical pesticides in that they ordinarily destroy only unwanted species, biocontrol agents (such as insects, fungi, and viruses) eat, infect, or parasitize targeted plant or animal pests. However, biocontrol agents can negatively affect nontarget species by, for example, competing with them for resources: a biocontrol agent might reduce the benefits conferred by a desirable animal species by consuming a plant on which the animal prefers to lay its eggs.

(Line 14)Another example of indirect negative consequences occurred in England when a virus introduced to control rabbits reduced the amount of open ground (because large rabbit populations reduce the ground cover), in turn reducing underground ant nests and triggering the extinction of a blue butterfly that had depended on the nests to shelter its offspring. The paucity of known extinctions of disruptions resulting from indirect interactions may reflect not the infrequency of such mishaps but rather the failure to look for or to detect them: most organisms likely to be adversely affected by indirect interactions are of little or no known commercial value and the events linking a biocontrol agent with an adverse effect are often unclear. Moreover, determining the potential (35) risks of biocontrol agents before they are used is difficult, especially when a nonnative agent is introduced, because, unlike a chemical pesticide, a biocontrol agent may adapt in unpredictable ways, so that it can feed on or otherwise harm new hosts.

24-6 The example presented by the author in lines 14-23 most clearly serves to illustrate

(A) a situation in which a species is less vulnerable to biocontrol agents than it would have been to chemical pesticides.

(B) a way in which the introduction of a biocontrol agent can affect a nontarget species.

(C) a nonnative agent’s adapting in an unpredictable way that results in damage to a new host.

(D) the contention that biocontrol agents can harm nontarget species by competing with them for resources.

(E) the way in which indirect consequences from the use of biocontrol agents are most likely to occurs.

请给解释一下B和E有什麽区别吗

juliaPL

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leeon

这是典型的举例作用题，原文在两个例子之前就是举例作用的答案：

However, biocontrol agents can negatively affect nontarget species by,

B就是原文；

E说使用生物控制的间接的结果最有可能发生；这里不是用来说明最有可能发生的。

juliaPL

也就是说E错就错在most likely 上了对吗，   but I really think if there is no B, E should be a right answer,

in fact, I select B also, but in case I just want to understand it more deeply

E选项的正确译法是否应为生物控制的间接的结果最有可能以什麽样的方式发生

leeon

以下是引用juliaPL在2004-11-3 2:12:00的发言：

也就是说E错就错在most likely 上了对吗，   but I really think if there is no B, E should be a right answer,

in fact, I select B also, but in case I just want to understand it more deeply

E选项的正确译法是否应为生物控制的间接的结果最有可能以什麽样的方式发生

你的译法没问题，这里很明显没有说明affect nontarget species 是最有可能发生的。所以E错误。如果是E，那么原文肯定是将affect nontarget species和其它生物控制的间接的结果比较，然后说明affect nontarget species是最有可能的。