life than ever before.In 1900,Americans' average lifespan was only 47 years,but today it is 75 years!When does old age begin then?Sixty-five may be out-of-date as the (4) D line between middle age and old age.After all,many older people don't begin to experience...
About a century ago, the average lifespan (寿命) for Americans was about 50 years.Today, the typical American lives for around seventy-eight years.According to a German aging study, the maximum lifespan in industrialized countries has increased by two years every decade since the mid 19th cent...
16.About a century ago.the average life-span for Americans was about 50 years.Today.the typical American lives for around seventy-eight years.According to a German aging study.the maximum life span in industrialized countries has increased by two year
According to a German aging study, the maximum life span in industrialized countries has increased by two years every decade since the mid 19th century. What accounts for such increased longevity Between 1900 and 1950, inventions such as refrigeration(制冷技术)and sewage treatment(污水处理) meant ...