绿叶鸟网（www.lvyeniao.cn）原创整理的 > 英语四级作文 Health Gains in Dloping Countries
1．以下图为依据描述发展中国家的预期寿命(life expectancy)和婴儿死亡率(infant mortality)的变化情况。
2．说明引起变化的原因。
In the dloping countries great changes took place in life expectancy and infant mortality in the period from 10 to 1990. In 10 life expectancy was very low, while infant mortality was very high. Howr, in 1990 life expectancy increased, whereas infant mortality declined.
There are many reasons for the changes, but in general, they come down to three major ones. First, their living conditions were improved. In the old days people in the dloping countries suffered ger and were exposed to the elements. Nowadays they are well fed and housed. Naturally they live longer than before. Besides, the medical condition was also improved and so the adequate medical treatment ensures the s' health and reduces infant mortality. Most important of all, ln the early 60s there were constant wars in some dloping countries because of the colonial rule and so a lot of people were killed in wars. Nowadays most dloping countries have become independent countries and their people live a peacel life.
In conclusion, the national independence and social stability are responslhle for these changes.
