I believe the answer would be C, burning fossil fuels. Oil and gas is made up of the remains of microscopic plankton. Over millions of years the remains become the carbon-rich coal, oil and gas we can use as fuel. When fossil fuels are burned they release carbon dioxide into the atmosphere, thus contributes to global warming.
C.
Article One of the United States Constitution establishes the legislative branch of the federal government, the United States Congress. ... Article One's Vesting Clause grants all federal legislative power to Congress and establishes that Congress consists of the House of Representatives and the Senate. - Wikipedia
Answer:
1.Where were they moving from? They were moving from rural area to urban areas.
2. Why did they flock to the big cities? They were moving to big cities in search of better paying jobs in the large factories.
Explanation:
Two biggest industrial revolutions have been seen in the history of the US.
The first wave was seen from 1700 to early 1800. This wave brought a rise in the factories.
The second wave was seen after the civil war. This wave bought rise in novel technologies such as telephones, vehicles, etc.
A large number of people migrated to the cities during these industrial revolutions in search of a better life.
