有些人造卫星被用于通讯，使我们可以把电话打到世界任何一个角落，收看电视直播，并通过互联网交流。有些被用于导航，这样地球上的人便可以在任何时刻都能够知道一个物体的方位，其精确度达到几米以内。
Some artificial satellites are used for telecommunications, which enable us to make telephone calls to any part of the world, to see live television transmissions and to communicate via the Internet. Other artificial satellites are used for navigation, so that people on Earth can know at any moment the position of an object, within a few meters.
(Source: wwenglish.com)