Pitch is the distance from the crest of one thread to the next. Because the vast majority of screw threadforms are single-start threadforms, their lead and pitch are the same. Single-start means that there is only one ridge wrapped around the cylinder of the screw's body.
Definition of metropolis. 1  1 : the chief or capital city of a country, state, or region. 2  2 : the city or state of origin of a colony (as of ancient Greece) 3  3a : a city regarded as a center of a specified activity an industrial metropolis a cattle metropolisb : a large important city one of Europe's great metropolises.
Central place theory (Walter Christaller): seeks to explain the number, size and location of human settlements in an urban system; settlements simply function as 'central places' providing services to surrounding areas; organized by hexagons to eliminate unserved or overlapping market areas.Central city: urban area that is not suburban; generally the older or original city surrounded by the newer suburbs. -Inner city: urban area around the CBD; typically poorer and more run down in the US and other long-developed states; typically more rich upscale in less-developed states.