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.

因为X和Y都是正整数，则只会发生两种情况，（X，Y）——（5，2）和（8，1）所以条件一说了X<8 则只会出现（5，2）的唯一情况，成立！条件二说Y>1 则也只能确定（5，2）的唯一情况，也成立呀！我选的D，就是一直找不出我的思维漏洞在哪，求解！

老师，听了OG精讲课程，老师是按照每个truck里面装三个shipments来解答的，但在这道题中并没有说到每个truck里装三个shipment，所以我觉得两个条件分别都不能，但合起来可以解答题目问题。请问我的思路有什么问题吗？

这题考点是so as to吗，为何这题E选项不能理解为to convert和for establishing平行呢

请问培月老师，看到选项我直接把DE排除了，因为airline被期望增加。。。这个语义很奇怪，应该是希望航空公司主动希望通过购买飞机来增加增加呀。所以在ABC里选了一个相对好的，请问这里的语义逻辑怎么考虑啊？

老师 428题我能选出来B（根据原文has led to...)但是在当时做题时我同时在纠结E选项。因为我不确定文中是在说说服还是在说需求。麻烦请郭培月老师解答一下～

我知道A和B错了，但是有个疑惑，““逗号”+非谓语”，所以A和B这里的prevented难道不是修饰主句的主语sound吗？为什么在这里用于修饰distances了呢。是老师说错了，还是我记错了？

C和E的排除中，老师给出的排除方法是在没有硬伤的情况下，主动优于被动，所以选择C选项。但是我当时的思路是，C当中的stationary在that的从句当中，只修饰到了troughts，而E当中的stationary则同时修饰crests和 troughts，在不知道troughts 和 crests是什么意思的情况下，我认为同时修饰两个要比单独修饰troughts好。就像以前那道uncontrolled和that was controlled那道题。

CDE排除的过程中，我的思路是who怎么能够就近修饰law firms呢，所以就选择了D，我也确实看到yet了，但是我认为可以做副词可以放过。请问我的思路有什么问题吗？

请问老师，这题条件二也推不出啊！条件二还有可能a大于1，这时候就不能确定x大于0了，所以是否答案应该选E？

最后留了ADE 觉得now部分应该作为结果伴随，排除A，在DE中选，因为about离knowledge越近越好，选了E 我想问问老师，1.这种ADE最后只有结构上的不同时，是由于句意重心导致选A的吗，着重强调现在有conclusion而非过去的研究；2.DE之间的对比，E把over 20年放中间来使得about。。离knowledge近是比D更好的吗。