地质学(geology)是
相信广大考生应该还记得中学时学过，地球的内部结构是一个同心状圈层构造，由地心至地表依次分化为地核(core)、地幔(mantle)、地壳(crust)。地球地核、地幔和地壳的分界面，主要依据地震波(seismic/earthquake wave)传播速度的急剧变化推测确定。如果把地球内部结构做个形象的比喻，它就像一个鸡蛋，地核就相当于蛋黄，地幔就相当于蛋白，地壳就相当于蛋壳。
从地球的外部结构来看，则可以分成大气圈(atmosphere)、水圈(hydrosphere)、生物圈(biosphere)和岩石圈(lithosphere)，岩石圈包括地壳和地幔上部。地球上有七大洲和五大洋，分别是亚洲(Asia)，欧洲(Europe)，北美洲(North America)，南美洲(South America)，非洲(Africa)，大洋洲(Oceania)和南极洲(Antarctica);太平洋(Pacific Ocean)，大西洋(Atlantic Ocean)，印度洋(Indian Ocean)，北冰洋(Arctic Ocean)和南冰洋(Antarctic Ocean)。
听力TPO1地质学讲座真题难点解析
讲座开篇
教授开门见山提出主旨Today I want to talk about a way in which we are able to determine how old a piece of land, or some other geologic feature is - dating techniques. ……It's fundamental.即dating technique is fundamental.年代测定技术是重要的。这里对应本篇讲座的第一题，主旨题What does the professor mainly discuss? 答案很明显为 B. The importance of a technique used for dating geological materials. 就是对开门见山的第一句话的一种同义转换。
那么，当我们知道文章的主线是讲Dating technique is important之后，同学们肯定会思考：什么是dating technique?或者哪种dating technique?为什么它重要，所以接下来就要重点听支持主旨句的细节信息。
讲座中间
接下来的第一句话非常重要，教授说Um… Take the Grand Canyon for instance.这里有大家熟悉的信号词take sth. for instance，典型的举例子讲课法。而例子要听举例主体，即专有名词Grand Canyon,教授会给出解释，为什么Grand Canyon可以说明年代测定技术的重要性。教授用了今昔对比的讲课法。在使用ULD这种新的dating technique之前，人们认为Grand Canyon的沙子来源于the sand had come from an ancient mountain range fairly close by that flattened out over time，即附近的一个山脉。但在使用ULD之后，认为沙子来源于half of the sand from the Grand Canyon was actually once part of the Appalachian Mountain阿帕拉奇亚山脉。这里对应第二题Before the use of uranium-lead analysis, where did most geologists think the Grand Canyon sandstone came from?考昔日观点，答案明显为D. A nearby mountain range that had flattened out over time.基本为文中原话。这是一个典型的细节信息。
之后，教授对ULD这个专有名词做进一步解释说明，用到了过程讲课法。听此类信息时，注意每一步骤关键词，主要为动词和名词(动作指向的对象)。因为这里可能考最难的一种题型-排序题，本题比较典型。原文为So if you measure the amount of Lead in the Zircon grain, you can figure out when the grain was formed. After that, you can determine the age of Zircon from different mountain ranges. Once you do that, you can compare the age of the Zircon in the sandstone in your sample to the age of the Zircon in the mountains. If the age of the Zircon matches the age of one of the mountain ranges, then it means the sandstone actually used to be part of that particular mountain range.本段比较专业，即使是做阅读理解，学生都会感觉难懂，所以这里必须借助合理的有效的笔记法来答题，即识别第一步骤动词measure ，第二步动词为determine，第三步为compare，最后一步为match，我们发现有了这四个关键词，第三题 In the talk, the professor describe the sequence of uranium-lead dating. Summarize the sequence by putting the events in the correct order. 排序题即可以做：正确的步骤为CBA，第三步没有考。A. Zircon in the sandstone is matched to the zircon in a particular mountain range. B. The age o zircon in a sandstone sample is determined. C. The amount of lead in sandstone zircon is measured. 我们发现本题选项中的关键词没有变化，只是将主动语态变为了被动语态。
接下来的第四题考查的是According to the professor, what change has caused uranium-lead dating to gain popularity recently?最近 ULD变的流行的主要原因是什么?答案为B. It can now be done more efficiently. 对应文中原话为But technical advances have cut down on the number of grains you have to study, so you get your results faster.转折之后的重点信息为本题答案，此技术现在变的更加有效。
讲座结尾
讲座的最后一段，教授认为这种新技术在未来会有大量的新的应用，并且用了举例子的方法讲了其中一种他自己想到的应用方式。这里对应第五题Why does the professor talk about the breaking apart of Earth's continents? 答案为A. To give another example of how uranium-lead dating might be useful。典型的举例子细节信息考点，问到了为何举例子，答案是例子前面的Topic。