Years before the advent of plate tectonics―the widely accepted theory, developed in the mid-1960's, the holds that the major features of Earth's surface are created by the horizontal motions of Earth's outer shell, or lithosphere―a similar theory was rejected by the geological community. In 1912, Alfred Wegener proposed, in a widely debated theory that came to be called continental drift, that Earth's continents were mobile. To most geologists today, Wegener's The origin of Continents and Oceans appears an impressive and prescient document, containing several of the essential presumptions underlying plate tectonics theory: the horizontal mobility of pieces of Earth's crust; the essential difference between oceanic and continental crust; and a causal connection between horizontal displacements and the formation of mountain chains. Yet despite the considerable overlap between Wegener's concepts and the later widely embraced plate tectonics theory, and despite the fact that continental drift theory presented a possible solution to the problem of the origin of mountains at a time when existing explanations were seriously in doubt, in its day Wegener's theory was rejected by the vast majority of geologists. Most geologists and many historians today believe that Wegener's theory was rejected because of its lack of an adequate mechanical basis. Stephen Jay Gould, for example, argues that continental drift theory was rejected because it did not explain how continents could move through an apparently solid oceanic floor. However, as Anthony Hallam has pointed out, many scientific phenomena, such as the ice ages, have been accepted before they could be fully explained. The most likely cause for the rejection of continental drift―a cause that has been largely ignored because we consider Wegener's theory to have been validated by the theory of plate tectonics―is the nature of the evidence that was put forward to support it. Most of Wegener's evidence consisted of homologies―similarities of patterns and forms based on direct observations of rocks in the field, supported by the use of hammers, hand lenses, and field notebooks. In contrast, the data supporting plate tectonics were impressively geophysical―instrumental determinations of the physical properties of Earth garnered through the use of seismographs, magnetometers, and computers. 我选了E considerable overlap前面是despite XXX说明这个是个成就，他和后面的反对W的观点的事情是相反的。所以感觉D说用这个词的目的是解释为啥W理论。请老师辨析DE！谢谢！

这一题，主要区别在于by trying to与in trying to，为何in trying to好与 by呢？ 还有一个区别是划线最后的have had to与have themselves to之间的区别，为何这里不能用have themselves to呢？尤其是在划线前面已经出现了have themselves to的情况下？

没思路，不知道结合条件一及条件二如何得出X1的值...脑子不好使！

只能做到50的阶乘，乘以2的50次方，再加1 的结果 但是后面怎么思考就不清楚了，遇到这种题该如何去做，有什么直接的方法吗？

请May老师帮忙梳理一下这个题怎么用A排列或者C组合的方法算出答案，我每次遇到这种题似乎都有点毛病，不知道应该用A还是C还是结合...

条件一不是已经表明P是C的数量的两倍吗？而原文条件也说明了P或者C其中任意一个都可能为2/3的总量，而条件一表明P=2C 则总份额就是3C。C/（P+C）=1/3，可以得出答案啊，为什么不能选？

这题我认为主要考点在if与when的连用上以及consider后面接to be或者直接接noun。如果在BC选项it无指代可以排除，ADE三个选项中为何E是最优选项呢？这里情形我认为if和when都呢说得通，而且consider后面接noun或者to be在语法上没有问题。

这题正确选项E为什么which后面没有动词而是接的不定式形式，如果这样which后面就不是完整的句子了啊？

How many positive prime numbers are less than integer n? a) 14<n<20。 b) 13<n<17

这一题C，D两个选项中明显有一点不同就是一个用了but many scientist，一个用了and mant scientist. 从句意来看的话，这句话说了A提出了一个观点，但是很多科学家怀疑，然后转折P这个人之后测出来了。虽然D选项中P做的事情用过去时优于C选项中P用完成时，但我认为C选项连词用的比D好，为什么这题D选项优于C选项？