Due to the domino theory, the United States was concerned about Vietnam because Vietnam had become the most powerful democratic nation in Asia. if Vietnam turned to communism, nearby nations might follow. Vietnam was offering economic aid to other nations to spread communism. if Vietnam became independent, the US would lose its hold on the region.

c. troops marched forward in close formation against newer, more accurate weapons

1) she is extremely upset

  the common sense as a pamphlet written by thomas paine. it promoted the independence of the colonies from british rule. the distribution of this pamphlet was great, it reached people everywhere and it was even read aloud at places people met. it also unite the colonists before the revolutionary war.

answer is d