gwd1 10,12 迷惑

dashasha

犯傻了，自己删掉自己的发言。

[此贴子已经被作者于2005-5-1 7:44:56编辑过]

ring_cheng

我的看法：选B

Although no one has quantified

changes in the rate of straying

as a result of the disturbances

caused by humans, there is no

(70)       reason to suspect that the effect

would be qualitatively different

than what was seen in the

aftermath of the laceType w:st="on">MountlaceType> laceName w:st="on">SaintlaceName>

laceName w:st="on">laceName>Helens eruption

GWD-1-Q12:

The author mentions the “aftermath of the Mount Saint Helens eruption” (lines 73-74) most likely in order to

1. provide an example of the process that allows the repopulation of rivers whose indigenous salmon population has become extinct
   



2. indicate the extent to which the disturbance of salmon habitat by human activity in one stream might affect the genetic structure of salmon populations elsewhere —>见原文：破坏的性质是一样的，什么叫性质严重？鲑鱼大量straying 就是性质严重。而extent正是对性质的严重性的概括，属客观事实 (might用法准确)
   



3. provide a standard of comparison against which the impact of human activity on the gene flow among salmon populations should be measured —>火山爆发后的高迷失率本身不能做为比较的标准，只是自然disturbance造成的后果；由它可以推知人类disturbance也会造成程度很严重的后果，即为B中的extent （看似比较，实为程度上的类推，B正确）


4. show how salmons’ homing instinct can be impaired as a result of severe environmental degradation of their natal streams  —>文中并未提及或INFER出鲑鱼的homing instinct被impaired,只是说它们被forced to stray and spawn ...      steelhead trout
   

   returning from the

   
   

   (60)       sea to spawn were forced to

   find alternative streams.


5. 
   
   show why straying rates in salmon populations remain generally low except when spawning streams suffer severe environmental disturbance

另外，我认为对gene flow和genetic structure不要过份抠字眼，其实正是disturbance造成了gene flow，才会进一步影响genetic structure的，两者有着紧密的联系。

[此贴子已经被作者于2005-5-17 17:47:57编辑过]

wwwhahchn

我认为12题应该选C，理由如下：

1.B)indicate the extent to which the disturbance of salmon habitat by human activity in one stream might affect the genetic structure of salmon populations elsewhere

the extent指the disturbance对genetic structure的影响程度，extent这个词本身就含有数量的意味，而第三段只说两者在质上的相同，因此用extent不对。而且，按照正常思维，既然要用MSH的例子来表明人类活动对基因结构的影响程度，那么在MSH的例子中作者一定会先说明volcanic eruption of MSH对基因结构的影响程度，可是第二段中volcanic eruption of MSH的影响在"As a consequence, their rates of straying, initially 16%, rose to more than 40% overall."这一句中体现，只说了对rates of straying的影响程度，并没有关于the extent to which volcanic eruption of MSH affect the genetic structure of salmon populations elsewhere的表述。因此判断不是indicate the extent ...

2.C)provide a standard of comparison against which the impact of human activity on the gene flow among salmon populations should be measured

这里的should be measured是说人类活动的影响应该如何来衡量，这和前面Although no one has quantified changes in the rate of straying as a result of the disturbances caused by humans(到目前为止还无法数量化)是不矛盾的。因为人类活动和自然现象造成的后果两者在本质上是相同的，不管人类活动不能使rates of straying从16%上升到40%这么多还是使rates of straying上升得更多，总之它一定是使rates of straying上升的，这就是它们的相同之处，也就是衡量the impact of human activity之比较标准，相当于一个在进行数量研究前就已经被公认的真理(理论上的)，如果在对人类活动进行数量研究之后得出的数据表明rates of straying从16%下降到了10%(for example)，那么根据之前确认的理论上的结论，这个数据应该是>16%，而不是<16%，所以10%这项数据一定是错误的。而且原文line71~72处的"different than"明显暗示是做对比了。

综上所述，答案应该是C

To be discussed ...

[此贴子已经被作者于2005-8-21 16:35:54编辑过]

yazi123

extent指disturbance影响其它地区基因（结构）的程度，见原文：（虽然没有记录straying rate变化的数字，但）破坏的性质/程度一样，即：人类和自然的disturbance都会造成鲑鱼的大量迷失。属客观事实(might用法准确)

楼上是不是理解错了？

原文是在说人类的影响和自然环境的影响有质的区别，即他们带来的影响没有可比性，那么既然如此，列举火山对鲑鱼的影响又怎么可能暗示了人类的行为的影响程度呢？

困惑！ 好像BC都不对

           there is no

(70)       reason to suspect that the effect

would be qualitatively different

than what was seen in the

aftermath of the laceType w:st="on">MountlaceType> laceName w:st="on">SaintlaceName>

laceName w:st="on">laceName>Helens eruption  

yazi123

there is no reason to suspect that 不就是说毋庸置疑。。。吗？ 怎么都理解反了？

我原来也选了B, 第三遍做这篇文章时，发现BC都不对。 只好选D,  也不觉得D有明显的错误

wwwhahchn

以下是引用yazi123在2005-5-10 23:05:00的发言：

there is no reason to suspect that 不就是说毋庸置疑。。。吗？ 怎么都理解反了？

我原来也选了B, 第三遍做这篇文章时，发现BC都不对。 只好选D,  也不觉得D有明显的错误

你理解反了~~

there is no reason to suspect that+从句=there is no reason to think that+从句，意即从句的内容是错的。

小女公子

Low levels of straying

are crucial, since the process

provides a source of novel

genes and a mechanism

      by which a location can be

(40)     repopulated should the fish

there disappear.  

想请教一下这句话的阅读。尤其是那个should the fish there disappear...

小女公子

up thanks

wwwhahchn

should the fish there disappear=if the fish there should disappear

小女公子

mao se dun kai

wu hu ai zai!!!