Cities do not appear on the earth randomly, nor do they grow in a random fashion. They develop as the result of a complex interplay of environmental and social factors.  Several factors in the natural environment determine the location of cities. Large cities, for example, are generally not found in inhospitable zones. Most major cities developed from villages and towns that grew up along shorelines, rivers, or railroads. The growth pattern of an urban settlement is also influenced by factors in the natural environment.  For example, mountains must be skirted, lakes must be avoided, and housing and industry must be placed conveniently near water and raw materials.  Social factors also influence the appearance and development of cities. For instance, a city may be established as a result of a political decision : prefix = st1 /Brazilcreated the new capital ofBrasiliain the midst of the jungle in order to stimulate the economic development there. Ideas about architecture and town planning also influence urban growth patterns. For instance, the pattern ofManhattanis the product of a planning decision made in 1811. Besides, the actual use to which land is put often depends on economic factors, because owners tend to devote their land to the use that gives them the greatest gain.  The location of particular social group is also influenced by ecological factors. Certain kinds of land use , such as parking lots , may quickly generate a disliked area and result in a mass departure of the original inhabitants. The location of the neighborhoods of different groups is thus related to such factors as their   income and to their feelings of group unity or prejudice against outsiders.  Social inventions such as the automobile and mass transit systems also influence urban patterns. If workers have to walk to their factories every day, their homes must be near the workplace, but if they can drive to work , they can easily live fifteen miles away. If large numbers of the urban labor force move away from the city centre , services and facilities will tend to follow them , perhaps leaving the city centre greatly changed. It can be inferred from the passage that people of low income
tend to live in big cities tend to live in small towns mostly live in city centers are likely to live together