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！

老师，我今天考试碰到的寂静题，一模一样！然后根本算不出来啊，两个式子结合是30x=5y.不知道寂静答案是怎么算出来x=15 y=90的？

请May老师解答～ 老师，您回复我的这一题，关于圆心角 和 圆周角，我有几个问题想问： 1. ABC是一个优弧，优弧的圆心角是怎么看的呢？为什么是∠BOC，而不是∠AOC呢？ 2. 此图中，（优弧）弧ABC 和 （劣弧） 弧AC是否有同一个圆心角 和 同一个圆周角呢？ 如果不是，老师可否分别把此图中 优弧与劣弧的圆心角和圆周角画一下？ 2. 优弧ABC所对应的圆周角 是∠E（我用红笔加上去的那一个）吗？

请May老师解答，想问一下鸡精的答案是不是错了？我的解答过程有没有问题？

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