[audioFiles]2016m6x/audio_ezfj_005_201605[/audioFiles]

游客2023-11-01  25

问题  

选项

答案                             Life Span
    About a century ago, the average life span for Americans was about 50 years. /Today, the typical American lives for around seventy-eight years. / What accounts for such increased longevity? /Between 1900 and 1950, inventions such as refrigeration and sewage treatment meant that/young people were able to survive longer. /Moreover, medical breakthroughs helped contain diseases/such as some fatal ones that killed many children. /These advances helped increase the average life span. /This means that future medical breakthroughs will result in even longer average life span.

解析
转载请注明原文地址:https://tihaiku.com/zcyy/3149579.html
最新回复(0)