Human beings have used tools for a very long time. In some parts of the world you can still find tools that people used more than two million years ago. They made these tools by hitting one stone against another. In this way， they broke off pieces from one of the stones. These chips of stone were usually sharp on one side. People used them for cutting meat and skin from dead animals， and also for making other tools out of wood.

　　Human beings needed to use tools because they did not have sharp teeth like other meat eating animals， such as lions and tigers. Tools helped people to get food more easily. Working with tools also helped to develop human intelligence. The human brain grew bigger， and human beings began to invent more and more tools and machines. The stone chip was one of the first tools that people used， and perhaps it is the most important. Some scientists say that it was the key to success of mankind.��

　　Since 1960 a new kind of tool has appeared. This is the silicon chip—a little chip of silicon crystal. It is smaller than a finger�瞡ail， but it can store more than a million “bits” of information. It is an electronic brain.Every year these chips get cleverer， but their size gets smaller， and their cost gets less. They are used in watches， calculators and intelligent machines that we can use in many ways.

　　In the future we will not need to work with tools in the old way. Machines will do everything for us. They will even talk and play games with us. People will have plenty of spare time. But what will they do with it？

　　Human beings used stone chips for more than two million years， but human life changed very little in that time. We have used silicon chips for only a few years， but life is changing faster every day. What will life be like twenty years from now？ What will the world be like two million years from now？��

　　24. The stone chip is thought to be the most important tool because it ______.��

　　A. was one of the first tools��

　　B. developed human capabilities��

　　C. led to the invention of machines��

　　D. was crucial to the development of mankind ��

　　25. At the end of the passage the author seems to suggest that life in future is ______.��

　　A. disastrous B. unpredictable C. exciting D. colorful

　　答案解析：

　　24. D） 這是一道細(xì)節(jié)題。根據(jù)文章第二段尾句 “Some scientists say that it was the key to the success of mankind”可知 “stone chip”對(duì)于人類(lèi)的發(fā)展起到了非常重要的作用，這與D正好相符。

　　25. B） 在文章最后一段中作者說(shuō)人類(lèi)在過(guò)去的幾百萬(wàn)年時(shí)間里一直使用“stone chip”，人類(lèi)社會(huì)發(fā)生的變化很小。而我們使用 “silicon chips”才不過(guò)幾年，生活卻發(fā)生了巨大的變化。于是作者發(fā)出了疑問(wèn)：“二十年后的生活會(huì)是什么樣子的呢？”，“ 二百萬(wàn)年后的世界又會(huì)是什么樣子呢？”，表明將來(lái)的生活無(wú)法預(yù)料，這與選項(xiàng)B相符。