Discussing Cause-2-revised

Over the past a hundred years, there has been a huge increase in population. There are several reasons causing this happened. First, advances in medicine and health care decrease the cases that people died from epidemic. Second, better sanitation and health habits also reduce the happening of epidemic, which can prevent people from being infected. Third, improved farming methods that produce more and better food, which can make people fed. Last, because of enough food and the advance of medical industry, fewer infant dead, and more people live longer. For these reasons, it is sure that the population increased in the past a hundred years.