老师您好能否帮我讲解下下面这个文章考试时该如何读，我读完这种文章压根不知道在说什么，只知道在讲ocean basin形成机制的几种理论。No very satisfactory account of the mechanism that caused the formation of the ocean basins has yet been given. The traditional view supposes that the upper mantle of the earth behaves as a liquid when it is subjected to small forces for long periods and that differences in temperature under oceans and continents are sufficient to produce convection in the mantle of the earth with rising convection currents under the mid-ocean ridges and sinking currents under the continents. Theoretically, this convection would carry the continental plates along as though they were on a conveyor belt (conveyor belt: n. 传送带) and would provide the forces needed to produce the split that occurs along the ridge. This view may be correct: it has the advantage that the currents are driven by temperature differences that themselves depend on the position of the continents. Such a back-coupling, in which the position of the moving plate has an impact on the forces that move it, could produce complicated and varying motions. On the other hand, the theory is implausible because convection does not normally occur along lines, and it certainly does not occur along lines broken by frequent offsets (an abrupt bend in an object by which one part is turned aside out of line) or changes in direction, as the ridge is. Also it is difficult to see how the theory applies to the plate between the Mid-Atlantic Ridge and the ridge in the Indian Ocean. This plate is growing on both sides, and since there is no intermediate trench, the two ridges must be moving apart. It would be odd if the rising convection currents kept exact pace with them. An alternative theory is that the sinking part of the plate, which is denser than the hotter surrounding mantle, pulls the rest of the plate after it. Again it is difficult to see how this applies to the ridge in the South Atlantic, where neither the African nor the American plate has a sinking part. Another possibility is that the sinking plate cools the neighboring mantle and produces convection currents that move the plates. This last theory is attractive because it gives some hope of explaining the enclosed seas, such as the Sea of Japan. These seas have a typical oceanic floor, except that the floor is overlaid by several kilometers of sediment. Their floors have probably been sinking for long periods. It seems possible that a sinking current of cooled mantle material on the upper side of the plate might be the cause of such deep basins. The enclosed seas are an important feature of the earth’s surface, and seriously require explanation because, in addition to the enclosed seas that are developing at present behind island arcs, there are a number of older ones of possibly similar origin, such as the Gulf of Mexico, the Black Sea, and perhaps the North Sea.

请看图

The Achaemenid empire of Persia reached the Indus Valley in the fifth century B.C., bringing (the Aramaic script with it, from which was derived both northern and ) southern Indian alphabets. A. the Aramaic script with it, from which was derived both northern and B. the Aramaic script with it, and from which deriving both the northern and the C. with it the Aramaic script, from which derive both the northern and the D. with it the Aramaic script, from which derives both northern and E. with it the Aramaic script, and deriving from it both the northern and 老师，上次答疑太卡，我后来听录音还是不太明白，题干不是说script derives from alphabets吗？ derive from 在这里改怎么理解？起源于？今晚有课，听不了答疑，麻烦老师讲解。

还有一个圆柱的的1/2中间切，直径是12ft，高是10ft，打横放的，没有一个半球面，没有一个底面，求表面积？ 另外一道机经和这个特别像，但是这个题说没有一个半球面，没有一个底面，看解析说要多加一个半圆的面积，不明白什么意思，麻烦老师讲解。

If r and s are positive integers, can the fraction r/s be expressed as a decimal with only a finite number of nonzero digits? 1 s is a factor of 100 2 r is a factor of 100 答案是A 这种题应该什么思路？ 不太会，答案没看懂。。。谢谢

at a certain company, a test was given to a group of men and women seeking promotions. If the average （arithmetic mean） score for the group was 80, was the average score for the women greater than 85? 1 the average score for the men was less than 75 2 the group consisted of more men than women. OG上给的答案太难记了，有简单一些的办法看出来吗？ 单看的话觉得是E

The Achaemenid empire of Persia reached the Indus Valley in the fifth century B.C., bringing (the Aramaic script with it, from which was derived both northern and ) southern Indian alphabets. A. the Aramaic script with it, from which was derived both northern and B. the Aramaic script with it, and from which deriving both the northern and the C. with it the Aramaic script, from which derive both the northern and the D. with it the Aramaic script, from which derives both northern and E. with it the Aramaic script, and deriving from it both the northern and 答案是C，错选了D。bringing the script with it 和 bringing with it the script 的区别不太清楚，只是感觉读起来没有后者顺，就把AB排除了。E的and并列在句中没有体现，排除。CD的derive应该指的是script，按理说应该是单数啊，为什么会选C？麻烦老师讲解。

我找的错误里有遗漏或多余的吗？谢谢 The following appeared as part of an article in a magazine devoted to regional life: "Corporations should look to the city of Helios when seeing new business opportunities or a new location. Even in the recent recession, Helios's unemployment rate was lower than the regional average. It is the industrial center of the region, and historically it has provided more than its share of the region's manufacturing jobs. In addition, Helios is attempting to expand its economic base by attracting companies that focus on research and development of innovative technologies." Discuss how well reasoned ... etc. 下面是我找的错误： 1.失业率降低和新商机没有因果关系 2.工业发达不适合吸引高科技 3.即便吸引高科技，也不能证明扩张经济

( Where once the union had acquiesced to the prejudices of its English-speaking members by supporting ) the imposition of an alien tax on immigrant workers, after 1897 the United Mine Workers made a determined effort to enlist Italians and Slavs in its ranks. (A) Where once the union had acquiesced to the prejudices of its English-speaking members by supporting (B) Where once the union acquiesced to it English-speaking members’ prejudice for the support of (C) While once the union had acquiesced to the prejudices of its English-speaking members in support of (D) While once the union acquiesced to its English-speaking members’ prejudice in supporting (E) While once the union had acquiesced to the prejudices of its English-speaking members in its supporting of 答案是A，错选了D。where once该怎么理解，而且时态也很难把握，我是根据后半句的made把用了过去完成时的选项都排除了。麻烦老师讲解。

During Roosevelt's years in office, Black Americans began voting for Democrats rather than Republic in nation electons, but Black support for Democrats at the state and local levels ( developed only after when civil rights legislation was supported by Harry Turman ). A. developed only after when civil rights legislation was supported by Harry Turman B. developed only after when Harry Turman supported civil rights legislation C. developed only after Harry Turman's support of civil rights legislation by Harry Turman D. develops only at the time after the supporting of civil rights legislation by Harry Turman E. develops only after there being Harry Turman's support of civil rights legislation 答案是C，错选了B。感觉C说的好绕，B的错误是only after 和when连用吗？麻烦老师讲解。

( Severe and increasing numerous critics are pointing to deficiencies in the British legal system, deficiencies that seem ) to deny a proper defense to many clients who are charged with crimes. A. Severe and increasing numerous critics are pointing to deficiencies in the British legal system, deficiencies that seem B. Severe and increasing numerous critics point to deficiencies in the British legal system, deficiencies seeming C. Severe and increasingly numerous critics are pointing to deficiencies in the British legal system that seem D. Severe and increasingly numerous critics point to deficiencies in the British legal system seeming E. Severe and increasingly numerous critics are pointing to deficiencies in the British legal system that seem 答案是C，错选了B。感觉后面应该有that seem，但是发现这个形式的ACE都是现在进行时，不明白为什么要用现在进行时。that seem和seeming的区别是什么？increasing numerous critics和increasingly numerous critics表达的意思是不是不同？麻烦老师讲解。