1. in the second industrial revolution, what led the way to new industrial frontiers? textiles, railroads, iron, and coal a true world economy, internal-combustion engines, and new products radios telephones,
light bulbs, and telegraphs steel,
chemicals, electricity, and petroleum

2. according to karl marx, the or working class, was oppressed by the middle class.

proletariat
bourgeoisie
socialists
communists

3. what elements made possible the second industrial revolution?
textiles,
railroads,
iron,
coal steel,
chemicals,
electricity,
petroleum earth,
air,
fire