GWD25-Q 13 to 15: Grassland songbirds often nest in the same grassland-wetland complexes as waterfowl, particularly in a certain 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. 虽然对waterfowl的一些措施可以使songbird收益,但是对其他生活的影响,尤其是对waterfowl predators的影响是很难预测的. For example, most predators of waterfowl nests prey opportunistically on songbird nests, and removing(15) these predators could directly increasesongbird nesting success. Alternatively, 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. 举例,比如迁移一些predators,它们尤其是以songbird nests为食,将可能直接让更多的songbird nest保留下来. 又或者,predators 主要以一些small mammals为食,这些small mammals也吃songbird nests.. Thus. Removing waterfowl-nest predators could affect songbird nesting success through subsequent increases(25) in small-mammal populations. 所以,把这些waterfowl-nest predators迁移走可以通过增加大量的small mammal populations来使songbirds的nest 存活。 觉得矛盾的地方:为什么把那些predators移走了,songbirds存活率就会增加呢?small mammals数量增加不是会导致songbirds nests同样减少吗?困惑ing 第一段结束 In 1995 and 1996, researchers trapped and removed certain waterfowl-nest predators. 95-96的时候,移除了一些predators. primary raccoons and striped skunks, then observed subse(30) quent survival rates for songbird nests. 主要是r和s,观察其后的存活率. Surprisingly. They observed no significant effect on songbird nestingsuccess. 令人惊讶的是,他们观察到移除这些predator并没对songbird nesting success有影响。 This may be due to several factors. Neither raccoons nor striped(35) skunks consume ground squirrels,which are important predators of songbird nests. Thus, their removal may not have led to significant increases in populations of smallerpredators. 分析原因。第一,是引文r和s都不吃S,S是songbirds nests的重要捕食者。所以,移除他们可能没有导致smaller predators的增加。 (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. 其次,r和s都比较喜欢wetlands一般不去upland habitats.所以移除这些生物不会导致 success of songbirds in uplands。。。。第二个理由也没看懂... 第二个理由也没看懂... 我就根据我没太看懂的比题目做一下,大家也帮着我看一看,先谢过...
我就根据我没太看懂的比题目做一下,大家也帮着我看一看,先谢过... ------------------------------------------------------------------------------------------------------- Q 13: NOTE: You must scroll to read the answer choices for this question.
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 water- fowl 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 com- pensate 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. 完全没思路,不知道选啥... 正确答案是A Answer: -------------------------------------------------------------------------------------- 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. Answer:C -------------------------------------------------------------------------------------- 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 E. propose that further experiments be performed to assess the long-term effects of certain wildlife management procedures answer:B     
[此贴子已经被作者于2007-7-10 13:19:06编辑过] |