A
Most people have map apps on their phones that can show their location and guide them to where they want to go. But how do these apps know your location at any time or place? They find you by using satellite navigation（satnav）systems（卫星导航系统）.
A satnav system uses groups of satellites to find the user’s location. This location information is then sent to a receiver, such as a smartphone.
The first satnav system was the Global Positioning System（GPS）,which belongs to the United States. First used in 1964, the system is the world’s leading satnav system. But China’s satnav system, Beidou, has overtaken（超过）GPS in size, Japan’s Nikkei Asian Review reported.
China sent Beidou’s first navigation satellite into space in 2000. China also became the third country to build a satnav system after the US and Russia, People’s Daily reported. As of right now, over 30 countries in Africa and the Middle East are using the Beidou system.
With its world-leading technology, Beidou is leading Chinese citizens to a better life by playing significant（重要的）roles in different areas，according to Xinhua News Agency.
For example, as of April, over 6.2 million vehicles（车辆）in China were using Beidou for navigation, according to a report on the Beidou system’s construction（建造）and development.
At the newly-built Beijing Daxing International Airport, Beidou has been used to keep track of（追踪）loading and unloading vehicles indoors and outdoors. When the airport fully opens, each baggage cart will have Beidou navigation equipment to help passengers get their luggage faster.
1. What do map apps depend on to find a user’s location?
A. satellites B. computers C. receivers D. smartphones
2. Which country built the world’s second satnav system?
A The US. B. Japan. C. China. D. Russia.
3. What do we know about the Beidou system?
A. Its first group of satellites was sent into space in 2001. B. It offers services to other countries.
C. The number of satellites it uses is the same as GPS. D. It has become the world’s best satnav system.
4. What do the last two paragraphs tell us?
A. Why most vehicles are using the Beidou system. B. How Beidou will improve service quality at airports.
C. How the Beidou system is being used. D. Who will be interested in using Beidou.
【答案】1. A 2. D 3. B 4. C
【解析】
【分析】本文是一篇说明文。文章介绍了中国在卫星导航系统上的发展和北斗给世界带来的便利。
1题详解】
细节理解题。根据第一段“But how do these apps know your location at any time or place? They find you by using satellite navigation（satnav）systems（卫星导航系统）.（但这些应用程序是如何知道你在任何时间或地点的位置的呢?他们通过卫星导航系统找到你。）”可知，地图应用程序依靠卫星来找到用户的位置。故选A。
【2题详解】
细节理解题。根据第四段“China also became the third country to build a satnav system after the US and Russia, People’s Daily reported.（据《人民日报》报道，中国也成为继美国和俄罗斯之后第三个建立卫星导航系统的国家。）”可知，是俄罗斯建造了世界上第二个卫星导航系统。故选D。
【3题详解】
细节理解题。根据第四段“As of right now, over 30 countries in Africa and the Middle East are using the Beidou system.（截至目前，非洲和中东地区已有30多个国家在使用北斗系统。）”可知，北斗系统向其他国家提供服务。故选B。
【4题详解】
主旨大意题。根据倒数第二段“With its world-leading technology, Beidou is leading Chinese citizens to a better life by playing significant（重要的）roles in different areas，according to Xinhua News Agency.（据新华社报道，凭借其世界领先的技术，北斗正通过在不同领域发挥重要作用，引领中国公民过上更好的生活。）”以及最后一段说明了北斗在北京大兴国际机场的具体运用，可知，最后两段主要告诉我们北斗系统是如何被使用的。故选C。
