The Lecturer mentions three magnets attracting citizen: town, country and town country. Additionaly, two plausible explainations of people's trend to move to city=> . The first thing brought out is economics. The unemployed who wants jobs and money flows to cities to track better career opportunities. By 1920, farming was the most popular job but now, when things can be done by machines, people tend to work in the field of IT, Financing, Tourism... The next reason is the standard quality of life which involves education, transportation, shops and entertainment. This leads to the result that the number of younger people in the city is much higher than that in the countryside. In contrast, old people seem to like life in the countryside than life in the city. Next, the lecturer brings forward 3 changes in the city. First of all, the city is getting bigger as there are more and more megacities with the population of over 20000. Second, the city is taller because land is more expensive so the only solution is making higher building to solve the problem of accommodation and unemployment. It is also spreading out in an uncontrollable way and linking to each other such as cities like Kyoto, cobia,.. in Japan. This brings about an impact on the quality of life in the city because they cannot provide us the best services. The third change is that the city is breaking up into smaller pieces in terms of ethnic group or income level. The consequence is people staying inside without communicate with others from different background. Finally, the lecturer expresses the hope that cities will continue to grow despite many challenging problems: security, comfort, poverty, crowding.