In my opinion, the 9-steps-Theory to Sufficiency from King Bhumibol provides a good definition of what asustainable city should be. The people should be able to produce food on their own so they can have enough toeat and live on. They should have good quality life which comprised of good social and economic status with nodebts. Moreover, people should find a way to live in harmony with nature by restoring and protecting, notdestroying the nature. Sharing with others is also important. This can contribute to a good society where giving ismore important than taking.