Question

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 phones. What do you do? Well, next time take a GPS with you. This invention may be able to help you. It is a device  which uses satellites (卫星) to find the user’s position(位置). It can find your position to within 20 meters. 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 it 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 its position. The third part of the system is a network of ground stations. They are all over the world. They control satellites and make sure they are working well.

    Some people think that in the future the GPS will be as common as the mobile phones. They are becoming cheaper and more and more accurate. There are also new uses for the GPS. Perhaps they will be like watches. Everyone will have one and you will never get lost again.

1.. According to the passage, with the help of the GPS, people __________.

A. can’t find their directions in different countries

B. can always find where they are

C. can learn about the culture of an unknown place

D. can spend the least time getting to another place

2.. The underlined word “They” in paragraph 3 means ____________.

A. Receivers     B. GPS devices    

C. Satellites     D. Ground stations

3. We can learn from the passage that ____________.

A. GPS can’t be put into a watch

B. GPS are becoming dearer and dearer

C. People can start their cars with a GPS

D. People can’t lose their way with a GPS when driving

Answer

1.B

2.D

3.D

【解析】

试题分析：这篇短文主要讲述了想象一下，你开着车一个人在沙漠里，你不知道自己在哪里。两个小时前你错过了最后一所房子。然后你的车抛锚了。时间是寒冷的黑夜，你没有手机。你该怎么办？然后重点介绍了GPS卫星定位系统的作用。

1.A GPS cannot start your car, but at least you will know where you are. GPS不能启动你的汽车，但是，至少你会知道你在哪里。故选B。

2.The third part of the system is a network of ground stations.这一部分主要介绍地面卫星接收站。故选D。

3.Everyone will have one and you will never get lost again.每个人有一个（GPS），你将永远不会迷路了。故选D。

考点：科普类阅读。