求问一题~阅读大全上的

哈嘻嘻

In most earthquakes the Earth’s crust cracks like porcelain, Stressbuildsup until a fracture forms at a depth of a few kilometers and thecrust (5) 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 (10) 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 the distance from the earthquake focus, or initial rupture point.

For most earthquakes, Wadati discovered, the interval was quite short near the epicenter; 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 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.

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


为什么选C，不选D哈？

哈嘻嘻

还有一题：Since the late 1970’s, in the face of a severe loss of market share in dozens of industries, manufacturers in the United States have been trying to improve productivity—and therefore enhance their international competitiveness—through cost-cutting programs. (Cost-cutting here is defined as raising labor output while holding the amount of labor constant.) However, from 1978 through 1982, productivity—the value of goods manufactured divided by the amount of labor input—did not improve; and while the results were better in the business upturn of the three years following, they ran 25 percent lower than productivity improvements during earlier, post-1945 upturns. At the same time, it became clear that the harder manufactures worked to implement cost-cutting, the more they lost their competitive edge.
With this paradox in mind, I recently visited 25 companies; it became clear to me that the cost-cutting approach to increasing productivity is fundamentally flawed. Manufacturing regularly observes a “40, 40, 20” rule. Roughly 40 percent of any manufacturing-based competitive advantage derives from long-term changes in manufacturing structure (decisions about the number, size, location, and capacity of facilities) and in approaches to materials. Another 40 percent comes from major changes in equipment and process technology. The final 20 percent rests on implementing conventional cost-cutting. This rule does not imply that cost-cutting should not be tried. The well-known tools of this approach—including simplifying jobs and retraining employees to work smarter, not harder—do produce results. But the tools quickly reach the limits of what they can contribute.
Another problem is that the cost-cutting approach hinders innovation and discourages creative people. As Abernathy’s study of automobile manufacturers has shown, an industry can easily become prisoner of its own investments in cost-cutting techniques, reducing its ability to develop new products. And managers under pressure to maximize cost-cutting will resist innovation because they know that more fundamental changes in processes or systems will wreak havoc with the results on which they are measured. Production managers have always seen their job as one of minimizing costs and maximizing output. This dimension of performance has until recently sufficed as a basis of evaluation, but it has created a penny-pinching, mechanistic culture in most factories that has kept away creative managers.
Every company I know that has freed itself from the paradox has done so, in part, by developing and implementing a manufacturing strategy. Such a strategy focuses on the manufacturing structure and on equipment and process technology. In one company a manufacturing strategy that allowed different areas of the factory to specialize in different markets replaced the conventional cost-cutting approach; within three years the company regained its competitive advantage. Together with such strategies, successful companies are also encouraging managers to focus on a wider set of objectives besides cutting costs. There is hope for manufacturing, but it clearly rests on a different way of managing.

The author suggests that implementing conventional cost-cutting as a way of increasing manufacturing competitiveness is a strategy that is
(A) flawed and ruinous
(B) shortsighted and difficult to sustain
(C) popular and easily accomplished
(D) useful but inadequate
(E) misunderstood but promising

为什么选D？