During the later half of the 20th century, the gap of the average life span between yenders(male and female)is becoming larger in quite a few developed countries and regions, but it is not the inexorable trend.

• 在 2 0世纪下半叶不少发达国家和地区分性别的人口平均预期寿命的差距在拉大 ,但并非必然趋势 ;