参考：
Good health is a改了 person's most valuble possession.today,it is much easier to be healthy than it was in 改了the past.Modern people know more about改了 health,have better food,and live in clean surroundings .Also ,scientists and doctors have改了 learned how to deal with many diseases.Most people can quickly get 改了help from a doctor or go to a hospital when改了 they are ill .As a result ,people in the modern world generally live longer than people was改了used to .People in developed countries can be expected改了 to live for twice as long as people who lived a little hundred years ago.
注意,每处改了的标记就是我所改的地方
希望对你有所帮助,学习愉快……