Answer:
Since Indian tribes living there appeared to be the main obstacle to westward expansion, white settlers petitioned the federal government to remove them. ... Under this kind of pressure, Native American tribes—specifically the Creek, Cherokee, Chickasaw, and Choctaw—realized that they could not defeat the Americans in war.
Explanation:
In simpler terms, the Native American tribes did not want to give up their land and America wanted to keep expanding ultimately into Native American land.
Answer:
European powers were no longer able to afford the resources needed to maintain control of their african colonies
Water is not made artificially, so when we get rid of water or pullute it, we are losing that natural recource, therefore making it limited.
The main reason why United States was involved in Vietnam is that the United States believed in the so called Domino effect: that if one country becomes communist, others might become communist too. So they got involved to stop the spread of communism (option a)
