发展中国家健康状况上升(Health Gains in Developing Countries)
from the graph we can see the health gains in developing cotmtries. in l960, the average life span or life expectancy was only 40 years old. in 1990, after thirty years, the life expectancy rose to 60. at the same time, with the life expectancy going up, the infant mortality is coming down. in 1960 the infant mortality was 200 dea