[求助]xdf补充-page79(16/22)

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 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 t 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（C）

(E) comparing the effects of shallow events with those of deep events

the answer is C, but i think it should be d

defending, predicting, 在原文中并没有体现啊。

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.

这到题a和c的区别在那里，我认为c更加忠实于原文“ the interval between their arrivals increases in proportion to (in proportion t adv.与...成比例) the distance from the earthquake focus (earthquake focus: 震源), or rupture point.”

大家看呢？

请指教

怎么没有NN回答呢？

ztlbox，我的答案和你一致，偶觉得xdf给的答案有问题。

偶的疑问也是这两题。呵呵。真巧。

同意两位的答案,我也正为这两提疑惑的说

同意楼主意见

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 that it flows instead of cracking, even under stress severe enough to deform it like putty.
How can there be earthquakes at such depths?
第一段提出地幔深处地震是否存在的问题。

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 t adv.与...成比例) the distance from the earthquake focus (earthquake focus: 震源), or rupture point.
第二段指出Kiyoo Wadati令人信服地证明地幔深处地震存在，并且指出了Kiyoo Wadati的新方法。

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.
第三段列出了两类不同地震在震波间隔和震动表现2个方面的不同表现。

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.
第四段列出了地幔深处地震的成因。

1.     The passage is primarily concerned with

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

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

(C) defending a revolutionary theory about the causes of earthquakes and methods of predicting them
第二段第1句：That such deep events do occur has been accepted only since 1927, when the seismologist Kiyoo Wadati convincingly demonstrated their existence.这里说明了作者的态度，他赞同Kiyoo Wadati的理论和方法。但确实没有指出predicting预测的方法，同时，defending也比较牵强，C应被排除。混

(D) discussing evidence for the existence of deep events and the conditions that allow them to occur（C）
地幔深处地震的evidence(实证)，文中确实通过论述Kiyoo Wadati的理论来给出了一些evidence，并进而提出了发生条件。我也赞同该选项。

(E) comparing the effects of shallow events with those of deep events
并非主旨，偏。

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.
不一定，如是浅层地震，而定点在很远处，也会有问题中的现象的。

(B) The earthquake was a shallow event.
可能，但也可能是深层地震。

(C) The earthquake focus was distant.
我认为正确。

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

(E) The earthquake had a low peak intensity.
震波间隔和震波峰值无关。

支持第一题的D.

对于第三题,我也选了C.分析时细看问题,还是C正确.大家把问题多看几遍就可以分出A和C的区别了.这种题属于有点绕的,有多个定位点,真真假假在一起.

我也认为第一题是D,第三题是C.

关于第三题,文中第二段最后一句说the interval between their arrivals increases in proportion to
                the distance from the earthquake focus
                , or rupture point.跟C选项内容一致.

弱弱的问，XDF补充题和XDF现在发的《商学院入学指导》有没关系呢～～

在那里可以下到单独的补充题呢～