概括：内容选自老托福听力，是练习托福听力的绝佳材料。


要什么hints啊，要什么提示啊，有也不给你~~嘿嘿
Not long ago, some of you may have read about a team of mountain-climbing scientists who helped to recalculate the elevation of the highest mountain in the world: Mt. Everest. Of course, the elevation of Mt. Everest was determined many years ago, using traditional surveying methods. But these scientists wanted to make a more precise measurement using a new method that takes advantage of recent advances in technology. It's called the Global Positioning System. The Global Positioning System uses 24 satellites that circle the Earth. Each of these satellites is constantly sending out signals. And each signal contains important information that can be used to determine the longitude, latitude, and elevation of any point on the Earth's surface. Well, in order to use this system to calculate Mt. Everest's elevation, scientists needed to put a special receiver on its summit to receive signals from the satellites. The problem with this was that, in the past, the receivers were much too heavy for climbers to carry. But now these receivers have been reduced to about the size and weight of a handheld telephone, so climbers were able to take a receiver to the top of Everest and, from there, to access the satellite system signals that would allow them to determine the precise elevation. And it turns out that the famous peak is actually a few feet higher than was previously thought.
有些人可能在不久之前听说了这样一队登山科学家，他们帮助重新测量了世界最高山峰——珠穆朗玛峰的海拔。当然，珠峰的海拔很多年前就已经尘埃落定，采用的是传统的测绘方法。但是，这些科学家希望借助科技的最新发展，采用新方法进行更为精确的测量。这就是全球定位系统。 全球定位系统利用了24个环绕地球的卫星。每个卫星皆会不停地发出信号，且每个信号中都包含了重要的信息，可以用来确定地球表面任何一点的经度、纬度和海拔。 为了采用该系统计算珠峰的海拔，科学家们需要在珠峰顶放置一个接收卫星信号的接收器。问题是，过去接收器太重，不可能让攀山员带上山。但是，现在，这些接收器只有手机的大小和重量了，因此，攀山员能够将其带到珠峰顶，从那里，接收卫星系统信息，然后确定珠峰精确的海拔。结果，著名的珠峰实际比之前所宣称的高度还要高几英尺。 ——译文来自: claire_fei