The communist regime of USSR led by Gorbachev was no longer willing to intervene in the eastern countries, in a time that the countries were facing increasing pressure for freedom and liberties. The success of some early uprising in countries like Hungary endeared other countries to follow suit.
Horrible conditions, including frostbite and starvation
Answer: The black gold, in 1859, when Edwin L. Drake was able to drill oil with the used of steamed engine
Explanation: Your Welcome!
