In the era after Wold War I and before the Great Depression, American towns grew rapidly mostly because of the Second Industrial Revolution, which gave way to a rise of factories both in and around major cities in the US.
Many of the people who have come to Mexico City have ended up living in "surrounding" areas, since life in the city itself is very fast paced and dense, meaning that many people wish to enjoy the benefits of the city without being there directly.
B is the answer because pangea is one super continent
The answer is a for u but i am not sure there has to be more explanation for this
To discourage a german invansion
