请教Prep-2-4-15

filman · 发表于 2008-6-23 22:11:00

以下是引用nuj_am在2007-9-22 16:48:00的发言：

试着说说吧,这题确实挺难的.

D项不管是温度还是压力给搞死的, 好歹是水自己把algae搞定的, 应该都不能undermine the validity of the conclusion.

但是如果是有微生物冲进来,把algae都吃了,那情况就不一样了.原文说algae讨厌就讨厌在Therefore, any particles of matter in the water, such as algae cells, that scatter or absorb light will interfere with the collection of heat.那么现在的微生物进来了自然也会有同样的效果, 这就好像一个黑帮搞掉了另一个黑帮, 换汤不换药, 老百姓还是倒霉. 但是要是老百姓把黑帮都打死了, 或者都饿死了(比如开店的都不交保护费哈), 那黑帮就彻底垮了. 我这个例子举的有点搞哈,大家放松一下

这道题我也做错了，回过头来想，是否可以这样理解。

从表面上看BCD似乎都起到undermine的作用。但是让我们回到题目，题目问的是seriously undermine the validity of the conclusions drawn from the experiment described in the last paragraph of the passage。有原文第二段第二句我认为这里undermine的关键是To repress the algae cells' capacity for accommodating themselves to environmental changes。B和D都属于cells' capacity for accommodating themselves to environmental changes，因而实际上B和D并没有起到Undermine的作用。因此答案是C。

Do you guys think my explanation makes sense?

Mandy2010 · 发表于 2011-5-29 17:25:59

If the algae is killed by microorganisms: Algae are dead but their buoyancy is not affected. They do not sink to the storage layer. The dead cells are still floating in the higher layer, preventing "the penetration of light to the deep storage area"

From Manhattan

shirryzhan · 发表于 2012-5-26 22:45:45

其实，大家想一下实验原理，这道题就豁然开朗。
Evaporation &Dilution ------ 破坏了algae的浮力导致其sank to bottom.
B The lateral motility of the algae cells that sank to the bottom of the pond was not impaired.
D The algae cells that sank to the bottom of the pond were actually killed by the rapid change in pressure
B和D，至少algae cells都sank to bottom了。
而C ‘The water with which the artificial solar pond was diluted contained microorganisms that kill algae.’ 则直接体现了实验的失败，在diluted water那个环节里出现了microorganisms kill algae，这个是实验中间的环节出错，所以后面algae的浮力可能不会被破坏，也就是不会下沉。

	B	C	D
Evaporation	Y	Y	Y
Dilution	Y	N	Y
Destroy Buoyancy--Sank to bottom	Y	?	Y

lonski · 发表于 2012-8-3 14:21:33

conclusion: This method allows for effective control of nuisance algae while leaving solar ponds as one of the cleanest technologies providing energy for human use.攻击可以从两个方面：有效性(effective control of nuisance algae)，或者清洁性（cleanest）

(A) The algae cells that sank to the bottom of the pond were destroyed only after a time lag of twenty-four hours.

只是下沉时间长，并不代表方法的有效性就undermine了。选项错误。

(B) The lateral motility of the algae cells that sank to the bottom of the pond was not impaired.
我之前也是选了这个选项。现在想想确实C更优。lateral motility虽然被impaired了，但并不严重损害effective control of algae,因为文中提到“the cells sank to the bottom of the pond, where they encountered the hot waters of the storage layer and were destroyed”，主要是海藻下沉导致被烫死了，"impairment to motility"这是指出这是个伴随现象，最重要的下沉原因是“Their buoyancy adversely affected”。选项错误。

(C) The water with which the artificial solar pond was diluted contained microorganisms that kill algae.

这个确实能杀死algae，effective control of algae是满足的。但是cleanest technolgy能否保证呢？看文中第三段对其他方法的担心“One proposed method of controlling the algae was the application of an algicide. However, the Dead Sea is a closed body of water without any outlet and as such is very easily contaminated.” C选项里面的microorganism就起到了algicide的作用，对死海的潜在污染风险很大，因此这个引入了microoganism，不能保证文中的方法是cleanest technology.这个选项正确。

(D) The algae cells that sank to the bottom of the pond were actually killed by the rapid change in pressure.
不管algae是被烫死的还是被压死的，反正方法的有效性是不会undermine的。与C比不好。

(E) The higher salinity brought about through evaporation increased the transparency of the upper levels of water in the pond.
与本题关系不大。增加transparency其实更能增加方法的有效性（透光更好）。选项错误。

cherryapple123 · 发表于 2016-1-2 11:59:52

lonski 发表于 2012-8-3 14:21
conclusion: This method allows for effective control of nuisance algae while leaving solar ponds as ...

同意！

Jagabee · 发表于 2016-12-6 16:44:18

nuj_am 发表于 2007-9-22 16:48
试着说说吧,这题确实挺难的.D项不管是温度还是压力给搞死的, 好歹是水自己把algae搞定的, 应该都不能underm ...

这个解释对我帮助很大，谢谢.

看到楼上也有详解提出了削弱结论要涵盖的两个方面，有效性和清洁性.

而我之所以错选b恰好是因为认为C中的微生物不算chemical而不会造成contamination.

看到你勾出的这个句子，才意识到即便微生物不算chemical不一定造成污染，但它会interfere with the collection of heat, 从而无法使polar ponds "provide energy for human use."

foodiesherry · 发表于 2017-7-28 15:47:23

发表一下个人看法
algea主要是能影响光线的穿过，但是algea如果沉底了就不会影响，所以能让algea沉底的方案都是可以得。
文章问的是削弱。
那么ABD都可以排除，不管是什么过程最后的结果都是algea沉底了，E是无关选项。
所以答案是C
首先algea被杀死不一定会沉底，而且新引入的微生物可以看做是污染也可以看做是另一个影响光线的因素。

请教Prep-2-4-15

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