All people, young or old, want to live a long life. The average lifespan in well – developed countries is about 65 – 70 years. People have a shorter newly – developed countries. In the past people had longer lives because the environment was more friendly and healthy to the man. The introduction of vaccination also prolonged the lifespan of many people. Nowadays people’s lifespan might be shorter because of the pollution of water, food and air.…
