p.136+summary+Life+Expectancy+SATOMI

Resent research has shown that people live longer in some countries and this is due to a number of causes. Firstly, because of waterworks we can use or drink clean water whenever and wherever and we live in safe environment which are separeted from conflict and wildlife. these have led to increase population. Secondly, as a result of development of technology and mental facilities, people live longer and older increase year by year. Recently some medicines save human life from serious disease.