11.  Secondly, with the development of developing countries, medical level is improved.

12.  Therefore, the general tentency of health gains rising can not change in Decades years , the people's living level is better and better .

13.  In this period, the level of living of china has increased and infrastructures of hospital and others all have increased.

14.  First, the life's level of the developing countries' people has already improved.

15.  Third, the people's culture level make them know how to keep themselves' body healthy.

16.  Latter , with the economy advancing and the society improving, people's life level is rising quictly .

17.  I think, life levels progress is the most .

18.  The key reasons were the high life level and developed medical technology.

19.  the level of people's life rised .

20.  In 1960 many developing countries had a bad economy, and people in those countries had a rather low living level, even they had not enough food to eat .