Why did urban areas develop subway, elevated train, and streetcar systems?

Which statement describes employment in the late 1800s

Which statement best describes standard oil in the late 1800s? standard oil controlled only a small number of the nation’s oil refineries. standard oil was a single business that operated in a small region. standard oil controlled only the means and methods of oil production. standard oil owned ninety percent of all oil refineries in the united states.

Why did the skill of writing disappear from mycenaean society