Answer: In the late 1800's and early 1900's, urban areas of the United States attracted thousands of immigrants because of the ready availability of industrial jobs.
SB's Answer:
B. The United States Constitution listed the colonists' reasons for rebelling against Great Britain, while the Declaration of Independence did not.
Why:
The Declaration of Independence was written during the period when America was still just 13 colonies and a part of Britain. In other words, the Declaration of Independence was a written declaration of America's wish for Independence from Britain. On the other hand, the Constitution was basically written as the standard laws and freedoms that all men are entitled to in order to prevent future generations from destroying the greatness that the founding fathers had worked so hard to create.
Poland, and parts of Belgium and the Netherlands. They were spared as the result of quarantined their borders and isolated themselves.
The answer here is the scientific study of behavior and mental processes.
In it's simplest terms psychology is the study of thoughts and behaviors. It can be applied to humans and animals so it's not restricted to just human behavior and mental processes.