[求助][求助]置疑大全2772答案GMAT-79-Q1and3

Across

Passage 79 (16/22)fficeffice" />

In most earthquakes the Earth’s crust cracks like porcelain. Stress builds up (build up: v.树立, 增进, 增大) until a fracture forms at a depth of a few kilometers and the crust slips to relieve the stress. Some earthquakes, however, take place hundreds of kilometers down in the Earth’s mantle, where high pressure makes rock so ductile that it flows instead of cracking, even under stress severe enough to deform it like putty. How can there be earthquakes at such depths?

That such deep events do occur has been accepted only since 1927, when the seismologist Kiyoo Wadati convincingly demonstrated their existence. Instead of comparing the arrival times of seismic waves at different locations, as earlier researchers had done. Wadati relied on a time difference between the arrival of primary (P) waves and the slower secondary (S) waves. Because P and S waves travel at different but fairly constant speeds, the interval between their arrivals increases in proportion to (in proportion to: adv.与...成比例) the distance from the earthquake focus (earthquake focus: 震源), or rupture point.

For most earthquakes, Wadati discovered, the interval was quite short near the epicenter (epicenter: n.震中, 中心), the point on the surface where shaking is strongest. For a few events, however, the delay was long even at the epicenter. Wadati saw a similar pattern when he analyzed data on the intensity of shaking. Most earthquakes had a small area of intense shaking, which weakened rapidly with increasing distance from the epicenter, but others were characterized by a lower peak intensity, felt over a broader area. Both the P-S intervals and the intensity patterns suggested two kinds of earthquakes: the more common shallow events, in which the focus lay just under the epicenter, and deep events, with a focus several hundred kilometers down.

The question remained: how can such quakes occur, given (in view of (in view of: adv.考虑到, 由于): CONSIDERING “given what she knew about others' lives, how could she complain about her own? Marilyn F.”) that mantle rock at a depth of more than 50 kilometers is too ductile to store enough stress to fracture? Wadati’s work suggested that deep events occur in areas (now called Wadati-Benioff zones) where one crustal plate is forced under another and descends into the mantle. The descending rock is substantially cooler than the surrounding mantle and hence is less ductile and much more liable to fracture.

1.                 The passage is primarily concerned with

(A) demonstrating why the methods of early seismologists were flawed

(B) arguing that deep events are poorly understood and deserve further study

(C) defending a revolutionary theory about the causes of earthquakes and methods of predicting them

(D) discussing evidence for the existence of deep events and the conditions that allow them to occur
(E) comparing the effects of shallow events with those of deep events

KEY; C

我觉得这个答案不对.应该是d, 不是c. 这片文章满简单的啊...求做过的讲讲. 文章里头没有methods of predicting them ....




还有第三题:

3.... It can be inferred from the passage that if the S waves from an earthquake arrive at a given location long after the P waves, which of the following must be true?

(A) The earthquake was a deep event.

(B) The earthquake was a shallow event.

(C) The earthquake focus was distant.

(D) The earthquake focus was nearby.（A）

(E) The earthquake had a low peak intensity.
大全的答案是a,可是我觉得a不对.第三段里头明明讲要两个条件才能判断是不是deep event, 这里只有一个条件, 只能是说focus远, 不能判断是不是深啊???

请求指点...

smm969672

1\ 我个人还是认为C对，P wave和S wave 的时间差，是测量地震是shallow events和deep events的方法，因为地震发生了，人的感觉是分不清的，只有靠这个来predicting,并非一般意义上的预测地震。


D不对的理由：文章讨论P wave和S wave 的时间差,是作为一种震源深浅的方法，而不是深层地震存在的证据，证据需要事物之外的东西，你不能说地震发生了，有P 和S两种wave，，两者时间间隔长，这是深层地震地震的证据，不合逻辑。恰恰相反，这是深层地震的结果。


3、distant用词不准。文章中的deep events 是several hundred kilometers down,
而shallow events也有几公里。怎么算distant?不严谨。文章中有：
Because P and S waves travel at different but fairly constant speeds, the interval between their arrivals increases in proportion to (in proportion to: adv.与...成比例) the distance from the earthquake focus (earthquake focus: 震源), or rupture point.


所以,只要 the S waves from an earthquake arrive at a given location long after the P waves
a deep event，肯定是真的。所以答案A保持原文严谨的逻辑。


    

Across

先谢谢杨老师帮小妹看题: 谢谢

以下是引用smm969672在2004-3-18 12:21:00的发言：

3、distant用词不准。文章中的deep events 是several hundred kilometers down,
而shallow events也有几公里。怎么算distant?不严谨。文章中有：
Because P and S waves travel at different but fairly constant speeds, the interval between their arrivals increases in proportion to (in proportion to: adv.与...成比例) the distance from the earthquake focus (earthquake focus: 震源), or rupture point.

所以,只要 the S waves from an earthquake arrive at a given location long after the P waves
a deep event，肯定是真的。所以答案A保持原文严谨的逻辑。


Because P and S waves travel at different but fairly constant speeds, the interval between their arrivals increases in proportion to (in proportion to: adv.与...成比例) the distance from the earthquake focus (earthquake focus: 震源), or rupture point.
这里说的是p,s之间的间隔时间越长,说明测量点和focus之间的距离越远.

It can be inferred from the passage that if the S waves from an earthquake arrive at a given location long after the P waves, which of the following must be true?
问如果s,p之间时间长,以下那个必定对???
朗文的解释: distant:FAR AWAY
far away in space or time
而且只有这一个含义. 我认为这个和题目里头的long after正好完美对应.

distance: dis‧tance
1.             AMOUNT OF SPACE
[uncountable and countable] the amount of space between two places or things
这是我们说的"距离"

要判断deep events和shallow event, 文章的条件很明确: 要3个
a1: long interval between s and p----------------------------------------->距离远
a2: but others were characterized by a lower peak intensity----------->强度小
a3: 测量地点是epicenter ------------------------------------------------>在正下方

三个条件都必要. 缺少任何一个都不能得到结论:----------: 地震发生在epicenter正下方地幔和地壳接触处

所以我认为此题肯定不是a. a的逻辑绝对不正确.
还请指教.


1题我再想想...

Across

谢谢

--        作者：smm969672
--        发布时间：2004-3-18 12:21:00

--        
1\ 我个人还是认为C对，P wave和S wave 的时间差，是测量地震是shallow events和deep events的方法，因为地震发生了，人的感觉是分不清的，只有靠这个来predicting,并非一般意义上的预测地震。

朗文当代上面的解释

pre‧dict     [transitive]fficeffice" />

    

to say that something will happen, before it happens

    

ￚsee also prediction
Sales were five percent lower than predicted.

    

D不对的理由：文章讨论P wave和S wave 的时间差,是作为一种震源深浅的方法，而不是深层地震存在的证据，证据需要事物之外的东西，你不能说地震发生了，有P 和S两种wave，，两者时间间隔长，这是深层地震地震的证据，不合逻辑。恰恰相反，这是深层地震的结果。


对,确实是结果,但是这个"结果"是伴随产生的, 就是利用这个能观察测量的结果来判断地震是否发生,发生的地点(focus)和观察的地点的距离.

    

    

杨老师请看偶的一段分析:

Passage 79 (16/22)

In most earthquakes the Earth’s crust cracks like porcelain. Stress builds up (build up: v.树立, 增进, 增大) until a fracture forms at a depth of a few kilometers and the crust slips to relieve the stress. Some earthquakes, however, take place hundreds of kilometers down in the Earth’s mantle, where high pressure makes rock so ductile (quiet and easily controlled) that it flows instead of cracking, even under stress severe enough to deform it like putty (固定窗户玻璃的腻子). How can there be earthquakes at such depths?
(第一段提出了一个貌似矛盾的背景和一个问题: How can there be earthquakes at such depths?)

That such deep events do occur has been accepted only since 1927, when the seismologist Kiyoo Wadati convincingly demonstrated their existence. Instead of comparing the arrival times of seismic waves at different locations, as earlier researchers had done. Wadati relied on a time difference between the arrival of primary (P) waves and the slower secondary (S) waves. Because P and S waves travel at different but fairly constant speeds, the interval between their arrivals increases in proportion to (in proportion to: adv.与...成比例) the distance from the earthquake focus (earthquake focus: 震源), or rupture point.
(第二段提出证明和判断方法之一的理论依据: P, S波的传播速度和时间的关系: 从focus震源到测量点, 时间越长, 距离越远)

For most earthquakes, Wadati discovered, the interval was quite short near the epicenter (epicenter: n.震中, 中心), the point on the surface where shaking is strongest. For a few events, however, the delay was long even at the epicenter. Wadati saw a similar pattern when he analyzed data on the intensity of shaking. Most earthquakes had a small area of intense shaking, which weakened rapidly with increasing distance from the epicenter, but others were characterized by a lower peak intensity, felt over a broader area. Both the P-S intervals and the intensity patterns suggested two kinds of earthquakes: the more common shallow events, in which the focus lay just under the epicenter, and deep events, with a focus several hundred kilometers down.
(结论是由两个明显条件和一个隐含条件得出结论: 有两种地震存在) (但是还是没有解释deep event的成因)



The question remained: how can such quakes occur, given that mantle rock at a depth of more than 50 kilometers is too ductile to store enough stress to fracture? Wadati’s work suggested that deep events occur in areas (now called Wadati-Benioff zones) where one crustal plate is forced under another and descends into the mantle. The descending rock is substantially cooler than the surrounding mantle and hence is less ductile and much more liable to fracture.
(解释原因)
(全文是明显的结构: 判断方法method, evidence---à现象存在existence---à现象成因conditions that allow them to occur)
所以我选了d

(C) defending a revolutionary theory about the causes of earthquakes and methods of predicting them


c不对的理由:
1.全文没有争议, defend就不好;

2.a revolutionary theory about the causes of earthquakes :没有提出任何新观点关于地震的成因(the causes of earth quakes are very clear: stress and fracture); 恰恰相反,地震的成因是用来解释深层地震的发生机理的

3. 如开头所书,predicting them是没有的.这里分析的都是地震发生后的事情,或者至少是发生同时的事情,没有预测

还请指教

lwei1016

姐姐,很佩服你的阅读的分析的彻底,但是个人觉得这样的分析过头了.因为这样很浪费时间,而且我觉得这样分析是可以提高整体的阅读能力但是这样分析我觉得会搞乱gmat作题的感觉的.个人意见啊.下面说说我的看法.看到你们这么认真,惭愧啊!


    


1题我觉得还是选c. 第一段说多数地震的原因,但是有些地震发生在地幔深处,其成因有所不同,再提出问题How can there be earthquakes at such depths?


二段说一个人有力的论证深沉地震的纯在,改变人们一前的看法三段写那个人的研究,将2种地震进行比较,四段回答一段的问题.


Some earthquakes, however, take place hundreds of kilometers down in the Earth’s mantle, where high pressure makes rock so ductile (quiet and easily controlled) that it flows instead of cracking, even under stress severe enough to deform it like putty (固定窗户玻璃的腻子). How can there be earthquakes at such depths?
注意这里的问句,其实是作者马上转到本文要说的对象上来了就是depth earthquakes.


2,3,4段都是再说这depth earthquakes.


现在看看D.discussing evidence for the existence of deep events and the conditions that allow them to occur.---讨论纯在depth events的证据和发生的情况条件.作者没有之谈论depth events还讨论和比较了与most earthquakes 的发生.所以不是只是讨论depth events.


C很难理解defend这个词,我的理解是作者没有说以前的方法的问题,只是作为引出要讨论的depth events的引子,作者主要是说这个W的新发现Instead of comparing the arrival times of seismic waves at different locations, as earlier researchers had done. Wadati relied on a time difference between the arrival of primary (P) waves and the slower secondary (S) waves     W这个兄弟的methods of predicting them,和以前的兄弟不一样的地方.


我觉得要理解作者同学的真正的写作意图是说的一个新的东东,主旨把握很重要.我去年第一次坐的时候也很纳闷,后来把它叫朋友翻译了一下,仔细的好好体会了一下,就想明白了.


不知道对你有没有帮助,嘿嘿.


    




    


    

lwei1016

55555,刚刚我回3题的帖子没有了.

lwei1016

3题主要是要看懂题目的long after ,


Both the P-S intervals and the intensity patterns suggested two kinds of earthquakes: the more common shallow events, in which the focus lay just under the epicenter, and deep events, with a focus several hundred kilometers down.说明p-s波时间差的时间短,是common shallow events.题目中时间差long,则说明是depth events.


D不对的理由：文章讨论P wave和S wave 的时间差,是作为一种震源深浅的方法，而不是深层地震存在的证据，证据需要事物之外的东西，你不能说地震发生了，有P 和S两种wave，，两者时间间隔长，这是深层地震地震的证据，不合逻辑。恰恰相反，这是深层地震的结果。Both the P-S intervals and the intensity patterns suggested two kinds of earthquakes文章直接说明了2中地震的划分.




这里要专个弯才能理解啊.请指教啊!

Across

以下是引用lwei1016在2004-3-18 23:37:00的发言：
55555,刚刚我回3题的帖子没有了.

谢谢啦先 hughug

下次记得,长的回复: 在word或者写字板里头存一下再贴过来..............我这里的东东都是在word里面作的.

bunnier

以下是引用pumpkin在2004-3-17 3:11:00的发言：

1.                 The passage is primarily concerned withfficeffice" />

(C) defending a revolutionary theory about the causes of earthquakes and methods of predicting them

(D) discussing evidence for the existence of deep events and the conditions that allow them to occur

KEY; C

我觉得这个答案不对.应该是d, 不是c. 这片文章满简单的啊...求做过的讲讲. 文章里头没有methods of predicting them ....

Agreed with you that there are not methods of earthquake prediction. Besides, the psg introduces W's theory rather than defend it.


(D) has a small issue in the use of term "events". If we can safely assume this term is used inter-changeably in place of "earthquakes", it's the most relevant answer. I would think we can do so... The first sentence of paragraph 2 and the last of paragraph 3:

Both the P-S intervals and the intensity patterns suggested two kinds of earthquakes: the more common shallow events, in which the focus lay just under the epicenter, and deep events, with a focus several hundred kilometers down.

bunnier

以下是引用pumpkin在2004-3-17 3:11:00的发言：

3.... It can be inferred from the passage that if the S waves from an earthquake arrive at a given location long after the P waves, which of the following must be true?fficeffice" />

(A) The earthquake was a deep event.

(C) The earthquake focus was distant.

大全的答案是a,可是我觉得a不对.第三段里头明明讲要两个条件才能判断是不是deep event, 这里只有一个条件, 只能是说focus远, 不能判断是不是深啊???

请求指点...

(A)    A deep event can't always be true... because it can be a shallow event that happens far away according to W's detection. If the question includes elements in paragraph 3, such as intensity and area, a deep quake can be determined.


(C) Deep or far means distant. A better choice.