61.  first , the living condition in developing countries has been improved quickly in the period of 30 years.

62.  Therefore the life of people is improved.

63.  This means our life is improving as fast as society.

64.  We must go all out to help the developing counties to improve their daily life.

65.  Another is the cost of their living has improved, they have rich food everyday .

66.  On the contrary, the life expectancy had been improved from 40 years old in 1960 to 60 years old in 1990.

67.  But by 1990 with the development of economy in many developing countries, people's living level had been improved greatly.

68.  People have the capacity to improve his life, and also have the quirement to live long more .

69.  So people can get enough food to eat and people's health condition is improved.

70.  This improved people's mental health.