Today, we talked about the population and settlement in the world. There are more than 7 billion people on the earth. That's too large to image what kind of sight is it when 7 billion people stay together. There are 73 million people born per year and 201,000 per day. That's really an amazing amount. I heard that the earth can stand 8 billion people at most. So these years, China contributed a lot for controlling the growth of population. In China, each family can only have one kid. And that makes the trend of growth in the world slow. Now, it will be cost 12 years to increase one billion people. We also talked about the life expectancy which means the average number of years to be lived by a group of people born in the same year. Depend on the area, different people in different areas have different life expectancy. But what the same is that woman has longer life expectancy than man. The reason for that is man always do the dangerous jobs which can not be done by woman.