732 medium- and short-wave broadcasting transmitting and relay stations, covering 92.1 percent of the population;

共有中、短波广播发射台和转播台732座，广播综合人口覆盖率达到92．1％；

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As its name suggests, it works by broadcasting a radar wave into the ground and interpreting (as any radar does) what is reflected back.

ECONOMIST: Winemaking and radar