题目内容：

    Competition is good for businesses. In the world of positioning systems, however, competition is also a must. 1. Now, China is building its own positioning system. It’s called Beidou.

China is only the third country in the world to own a positioning system. Only the United States and Russia have already developed their GPS or Glonass.

2.With it, the country no longer has to rely on foreign systems. It also shows the world that China has made much technological progress.

Work on the Beidou project began in 1994. However, the first two Beidou satellites were not sent into space until 2000. 3.These satellites have formed a global network. They began operations at the end of 2018. To further improve the system, China will send ten more Beidou satellites into space. It plans to complete the system before 2020.

4.It will provide a positioning accuracy of within ten centimeters for the Chinese military. The United States’ GPS only has an accuracy of around 30 centimeters.

The Beidou system offers services to ordinary users, too. In big cities like Shanghai, thousands of buses have been using the Beidou system. 5.

Moreover, most smartphones today can already receive Beidou signals. A phone salesperson in Beijing jokes, “Many people are used to saying, ‘I am using GPS.’ In fact, however, their phones have been using Beidou.”

根据短文内容，从方框中选出五个句子填入文中空缺处，使短文内容通顺完整。

A.Since then, China has launched dozens of Beidou satellites.

B.It is not wise for a country to rely on foreign systems for positioning.

C.People waiting for a bus can easily find out when it will come.

D.The American GPS, Russia’s Glonass have dozens of satellites to provide information across the globe.

E.The completed system will be more powerful than any existing foreign systems.

F.Beidou improves China’s national safety.