2013年3月16日托福阅读真题回顾.doc

2013年3月16日托福阅读真题回顾 来源：朗阁培训中心　　编辑：xm　　发布日期:2013-03-20 摘要：厦门朗阁培训中心为烤鸭们整理了3月16日托福阅读考题回顾以及备考建议。 根据话题对应，可重点结合TPO11 Orientation and Navigation; TPO15 A Warm-blooded Turtle; TPO16 Planets in our Solar System三篇文章阅读。 　　1、我们如何计算太阳系的年龄 　　如何计算地球的年龄，地球表面由于水和风华作用影响底层，不易推算，但是可以通过研究meteor三种分别是rocky，irony，和rocky-irony。介绍了他们的来源，大部分是裂解的大型陨石。 　　我们推断出地球大约形成在64million年前左右，同时科学家还发现了月球的一个meteor致是这个时间，而由于月球表面不容易风华，这个时间应该是准的。 　　最后我们都通过检测其他星球传来的wavelight的波长推算出宇宙在膨胀，星系之间的距离在变远。 　　AGE OF THE EARTH 　　So far scientists have not found a way to determine the exact age of the Earth directly from Earth rocks because Earths oldest rocks have been recycled and destroyed by the process of plate tectonics. If there are any of Earths primordial rocks left in their original state, they have not yet been found. Nevertheless, scientists have been able to determine the probable age of the Solar System and to calculate an age for the Earth by assuming that the Earth and the rest of the solid bodies in the Solar System formed at the same time and are, therefore, of the same age。 　　The ages of Earth and Moon rocks and of meteorites are measured by the decay of long-lived radioactive isotopes of elements that occur naturally in rocks and minerals and that decay with half lives of 700 million to more than 100 billion years to stable isotopes of other elements. These dating techniques, which are firmly grounded in physics and are known collectively as radiometric dating, are used to measure the last time that the rock being dated was either melted or disturbed sufficiently to rehomogenize its radioactive elements。 　　Ancient rocks exceeding 3.5 billion years in age are found on all of Earths continents. The oldest rocks on Earth found so far are the Acasta Gneisses in northwestern Canada near Great Slave Lake (4.03 Ga) and the Isua Supracrustal rocks in West Greenland (3.7 to 3.8 Ga)， but well-studied rocks nearly as old are also found in the Minnesota River Valley and northern Michigan (3.5-3.7 billion years)， in S