the city are most place people live
in the world are more than 7.021.836.029 people. And more than the 75%live in citys.
the most problems are the food , the have to go to the job.
ther are many city and in ech city have a diferent clime in madrid is hot and not much rain .In tokyo is coold and it rains to much. The citys are many population. Some ways to travel in a city are train car bus or walking.
Each city have diferents problems like security. like Venice.