Howdopeoplefindtheirways?Atfirst,peoplediditbylookingat...

問題詳情：

How do people find their ways? At first, people did it by looking at the sun, the moon and stars. Later, we started to use the compass（指南針）. Today, there are navigation satellite systems.

A navigation satellite system uses groups of satellites. They send information to a receiver, such as your smart phone. Then they can find where you are.

The earliest navigation system is the Global （全球的） Positioning System（GPS）of the United States. The US has put 24 satellites into space to make sure GPS can locate a person correctly and globally. Russia's GLONASS and European Union's Galileo can also work globally.

The BeiDou Navigation Satellite System （BDS）is China's homegrown navigation system. It was set up in 2000. With it, China became the third country to build a navigation system after the US and Russia.

BeiDou can find you wherever you are. It helps you go faster by finding shortcuts and using correct directions. When you are in trouble and call the police, they will know exactly where you are if you have a smart phone that uses BeiDou.

Today, there are more than 20 BeiDou satellites above our head. And the system is able to offer open services to the Asia﹣Pacific area.

China plans to send more BeiDou 3 satellites into space. BeiDou﹣3's position accuracy（精確度） is less than five meters. By 2020, the BeiDou system will have 35 satellites and begin serving Globally.

24. How did people find their ways at first according to this passage?　   　

A. By looking at the sun, the moon and stars.

B. By using the navigation satellite systems.

C. By looking at the compass.

25. How many navigation satellite systems are mentioned in the passage?　   　

A. Two                         B. Three                       C. Four

26. What does the underlined word"locate "in the third paragraph mean? 　   　

A. 位於                        B. 設置                        C. 定位

27. What do you know about the BeiDou system?　   　

A. It was set up before GPS.

B. It will begin serving globally by 2020.

C. There are less than 20 BeiDou satellites today.

【回答】

24.A

【解析】細節理解題。根據短文第一段中At first, people did it by looking at the sun,  the moon and stars可知，起初人們通過觀察太陽、月亮和星星來做到這一點，由此可知選A。

25.C

【解析】細節理解題。根據短文第三段中The earliest navigation system is the Global （全球的） Positioning System（GPS）of the United States. Russia's GLONASS and European Union's Galileo can also work globally.可知，這裏提到了GPS、 GLONASS和Galileo三個；再加上*的BDS，一共是四個，故*是C。

26.D

【解析】詞義猜測題。根據短文第二段中A navigation satellite system uses groups of satellites. They send information to a receiver, such as your smart phone. Then they can find where you are可知，*系統可以找到我們在什麼地方，即“定位”。第三段中The US has put 24 satellites into space to make sure GPS can locate a person correctly and globally提到的是美國的*系統，這一系統能夠準確地定位一個人。由此可知locate這個單詞的意思是“定位”，故選D。

27.B

【解析】細節理解題。根據短文最後一段By 2020, the BeiDou system will have 35 satellites and begin serving Globally可知，到2020年，北斗系統將擁有35顆衞星，並開始向全球服務。由此可知*是B。

知識點：科普環保類

題型：閲讀理解