Building on a Soviet-era foothold, Russia is expanding its monitoring stations for Glonass, its version of the Global Positioning System ( ' , GPS).

出自-2016年12月阅读原文

Building on a Soviet-era foothold, Russia is expanding its monitoring stations for Glonass, its version of the Global Positioning System GPS.

2016年12月六级真题（第三套）阅读 Section B