求翻译：政府提出，到2020年，要基本建立覆盖城乡居民的社会保障体系.由于中国人口约占社会人口的五分之一，届时，它将成为世界上最大的社会保障体系是什么意思？

Government, 2020, to establish urban and rural residents basic social security system because of China's population accounts for about one-fifth of our population, then, it will become the world's largest social security system

The Government, in the year 2020, it is necessary to establish a coverage of urban and rural residents due to China's social security system, the population is about 5 hours of socio-demographic, and at that time, it will become the world's largest social security system

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The Government, by 2020, to establish the social security system of covering urban and rural residents Basic. as China's population of about one-fifth of the total population, by which time it will become the world's largest social security system

正在翻译，请等待...