1.Imagine the situation.You are driving along a desert or on a mountain.You have no idea where you are.You passed the last house two hours ago.Then your car breaks down.It is night and it is cold.You have no mobile phone.What do you do?Well,next time take a GPS with you.This invention may be able to help you.It is a device(装置) which uses satellites (卫星) to find the user's position(位置).It can find your position to within 20metres.A GPS cannot start your car,but at least you will know where you are.
GPS,which means Global Positioning System,is a small radio receiver.It looks like a mobile phone.You can hold it in your hand,or put in your pocket.It is sometimes put into a watch or a telephone.We also find GPS devices in cars,planes,or boats.Some of these devices have electronic maps,so you know where you are.For example,in a city they can tell you the name of the street.
There are three parts to the Global Positioning System.The first part is the receiver.You can hold it in your hand,or have it fixed into your car,plane,etc.The second part is a group of satellites orbiting the Earth.The receiver contacts at least four of the satellites and calculates(计算) its position.The third part of the system is a network of ground stations.They are all over the world.They control the satellites and make sure they are working well.
Some people think that in the future the GPS will be as common as the mobile.They are becoming cheaper and more and more accurate(精确的).There are also new uses for the GPS.Perhaps they will become like watches.Everyone will have one and you will never be lost again.
55.According to the passage,with the help of the GPS,peopleA.
A.can't be lost in a new city
B.can't find their way in different countries
C.can learn about the culture of an unknown place
D.can spend the least time getting to another place
56.The underlined word"They"in paragraph 3means"D".
A.Receivers
B.GPS devices
C.Satellites
D.Ground stations
57.What can we infer(推断) from the passage?D
A.All GPS devices have electronic maps.
B.People in many countries will use the GPS for free.
C.The receiver of the GPS contacts at least five of the satellites.
D.The GPS will become more and more common in everyday life.
分析 这篇短文介绍GPS定位系统.它可以在20米内搜寻到你的位置,非常方便.有些装置还置有电子地图,并预测了为来的定位系统将会非常普及
解答 55.A细节理解题.根据短文第一段It can find your position to within 20 metres.A GPS cannot start your car,but at least you will know where you are.描述,可知卫星定位系统能让你知道自己在哪儿.故选A,不会在新城市中迷路.
56.D理解推断题.联系上句The third part of the system is a network of ground stations.描述,可知指的是地面接收站.故选D.
57.D主旨大意题.根据短文最后一段Some people think that in the future the GPS will be as common as the mobile.They are becoming cheaper and more and more accurate(精确的).There are also new uses for the GPS.Perhaps they will become like watches.可知卫星定位系统在日常生活中会变得越来越普通.故选D.
点评 做题时要在理解好文意的基础上,与题目有机的结合,从文章中找到相关细节性的句子与选项细细比对,进行选择或推理判断,选出符合文章内容的正确选项.做题注意灵活,有时可采用排除法或直选法确定出最终答案.