[求助]GWD-25-Q13

司香尉

GWD-25-Q13-Q15

Grassland songbirds often nest in

the same grassland-wetland complexes

as waterfowl, particularly in a certain

Line part of those complexes, namely,

 (5) upland habitats surrounding wetlands.

Although some wildlife management

procedures directed at waterfowl, such

as habitat enhancement or restoration,

may also benefit songbirds , the impact

(10) of others, especially the control of

waterfowl predators, remains difficult to

predict. For example, most predators

of waterfowl nests prey opportunistic-

ally on songbird nests, and removing

(15) these predators could directly increase

songbird nesting success. Alterna-

tively, small mammals such as mice

and ground squirrels are important

in the diet of many waterfowl-nest

(20) predators and can themselves be

important predators of songbird

nets. Thus. Removing waterfowl-nest

predators could affect songbird nesting

success through subsequent increases

(25) in small-mammal populations.

In 1995 and 1996, researchers

trapped and removed certain waterfowl-

nest predators. primary raccoons and

striped skunks, then observed subse-

(30) quent survival rates for songbird nests.

Surprisingly. They observed no sig-

nificant effect on songbird nesting

success. This may be due to several

factors. Neither raccoons nor striped

(35) skunks consume ground squirrels,

which are important predators of song-

bird nests. Thus, their removal may

not have led to significant increases

in populations of smaller predators.

(40) Additionally, both raccoons and striped

skunks prefer wetlands and spend little

time in upland habitats; removing these

species may not have increased the

nesting success of songbirds in the

uplands enough to allow detection.

 

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Q 13:

 

According to the passage, which of the
   following is true about the role played
   by ground squirrels in the ecology of
   grassland-wetland complexes?

 

A.    While not important in the diet of
     raccoons or striped skunks, ground
     squirrels are a significant source
     of food for other waterfowl-nest
     predators.

B.     Whereas ground squirrels are
   typically important as predators of
   songbird nests, their opportunistic
   predation on waterfowl nests also
   has an observable effect on waterfowl nesting success.

C.     Although most waterfowl-nest
   predators prey on small mammals
   such as mice and ground squirrels,
   populations of ground squirrels tend
   to increase quickly enough to compensate for this level of predation.

D.    Although ground squirrels have been
   known to prey on songbird nests, a
   larger portion of their diets is usually
   provided by predation on waterfowl
   nests.

E.     Since larger predators tend to prefer
   small mammals to songbird eggs as
   a food source, a large population of ground squirrels plays an important
   role in controlling opportunistic
   predation on songbird nests.

答案是A，请问B为什么不对呢？我觉得就题目中说土拨鼠在鸟的生态均衡系统中起的作用而用，应该是B更加切题才对啊。A说的是土拨鼠作为人家的食物，***不吃它，但是其他的要吃它，和在鸟的生态均衡系统中起的作用没关系啊。

[此贴子已经被作者于2006-5-26 14:46:54编辑过]

Iawfy

ground squirrels are important for waterfowl-nest predators, but when researchers removed some reccoons and skunks, the effect on songbird nesting is not very significant.  therefore,  ground squirrels are not important in the diet of raccoons and striped skunks, but do for other predators.
the answer is A

司香尉

那么B到底为什么错呢？

如果要把实验结合起来的话，A对B错，因为实验中土拨鼠没起到什么作用。是不是应该这样理解这道题目啊？

司香尉

刚才又看了一遍文章，知道B为什么错了。

Whereas ground squirrels are
  typically important as predators of
  songbird nests, their opportunistic
  predation on waterfowl nests also
  has an observable effect on waterfowl nesting success.

后半句不对，文中没有提到土拨鼠吃水鸟，只是说土拨鼠吃songbird 。我太粗心啦。

[此贴子已经被作者于2006-5-27 15:10:59编辑过]

MaccMichAA

waterfowl predator 吃 squirrels 吃 songbird

waterfowl predator 也可直接吃songbird

对我来说 B关系 文章没有提过 我也推不出来

ly365

ding

星之枫

搂主可不可以把这篇阅读的三个问题和答案贴出来啊，因为刚看到jj有这篇阅读，所以想看看。找了半天没找到。谢谢

司香尉

Q 14:

Which of the following best describes
            the function of the sentence “Neither
            raccoons…songbird nests” (lines 34-37)
            in the context of the passage as a whole?

 

A.     It raises questions about the validity of a
            theory described in the first paragraph.

B.     It points out an oversimplification that is
            inherent in the argument presented in

the first paragraph.

C.    It introduces information that may help
                explain the results of the experiment
                that are presented earlier in the
                paragraph.

D.    It provides a specific example of the type of data collected in the experiment
            described earlier in the paragraph.

E.     It anticipates a potential objection to the conclusions drawn by the researchers
            involved in the experiment described
            earlier in the paragraph.

 

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Q 15:

The primary purpose of the passage is to

 

A.     describe some procedures used for
            wildlife management and consider
            some problems associated with the execution of those procedures

B.    outline a problem related to a wildlife
                management procedure and offer
                potential explanations for the results of
                an experiment bearing on that problem

C.     present experimental results that illustrate the need for certain wildlife
            management procedures and point out
            some inconsistencies in those results

D.    argue that a certain procedure used
            for wildlife management should be
            modified because of its unintended
            consequences

propose that further experiments be
    performed to assess the long-term
    effects of certain wildlife management
    procedures

nimabide

waterfowl predator 吃 squirrels 吃 songbird
waterfowl predator 也可直接吃songbird
对我来说 B关系 文章没有提过 我也推不出来

-- by 会员 MaccMichAA (2006/10/14 13:44:00)

不是说吃的nests么，没说直接吃那个鸟啊