从历史上看,人类平均寿命不断地随时间推移而逐渐延长。两千年前人类平均寿命为20岁,到18世纪为30岁。19世纪末为40岁,当前,20世纪80年代已达70岁。我国的平均寿命也在不断延长,全国解放前为30多岁,到1980年已增加到68.2岁。 随着平均寿命的不断增加,我国高龄老人逐 Historically, the average human life expectancy has been gradually extended over time. Two thousand years ago, the average human life expectancy was 20 years, to the 18th century to 30 years. The late 19th century was 40 years old, at present, the 20th century, 80 years has reached 70 years old. The average life expectancy of our country is also constantly on the rise. It was over 30 years before the liberation of the country and increased to 68.2 years by 1980. With the continuous increase of average life expectancy, the elderly in our country will go by themselves