The correct answer is Innovators developed a process to produce steel inexpensively.
The Second Industrial Revolution was born with scientific and technological progress that occurred in England, France and the United States, around the second half of the 19th century.
The discovery and use of new energy sources - oil (in the combustion engine), water (in hydroelectric plants), uranium (for nuclear energy), have further revolutionized industrial production. The list of inventions and discoveries is huge, which represented greater comfort for the human being.
