Interchangeability
71Rail transport modelling — Rail transport Operations Track Maintenance High speed Gauge Stations …
72Narrow gauge railway — Track gauge by size Broad gauge St …
73Natural gas — For other uses, see Natural gas (disambiguation). Natural gas extraction by countries in cubic meters per year. Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons[1] …
74Postmodernism — This article is about the philosophy. For the condition or state of being, see Postmodernity. Postmodernism preceded by Modernism Postmodernity …
75Wade-Giles — RCL Wade Giles (pronEng|ˌweɪdˈʤaɪlz; zh stp|s= or |t= or |p=wēituǒmǎ pīnyīn), sometimes abbreviated Wade, is a Romanization system (phonetic notation and transcription) for the Mandarin language used in Beijing. It developed from a system… …
76Zeus — For other uses, see Zeus (disambiguation). Zeus …
77Pendulum — This article is about pendulums. For other uses, see Pendulum (disambiguation). Simple gravity pendulum model assumes no friction or air resistance …
78Micrometer — This article is about the measuring device. For the unit of length, see Micrometre. Outside, inside, and depth micrometers A micrometer (   …
79Ohm's law — This article is about the law related to electricity. For other uses, see Ohm s acoustic law. V, I, and R, the parameters of Ohm s law. Ohm s law states that the current through a conductor between two points is directly proportional to the… …
80Hmong people — Flower Hmong in traditional dress at the market in Bắc Hà, Vietnam Total population 4 to 5 million …