Why would a researcher use a primary source instead of a secondary source when analyzing a a historical event

Need the draft was suspended largely because a. american public opinion opposed it. b. the president vetoed it. the supreme court declared it unconstitutional. d. world war ii ended.

Why did win shihuangdi force all nobles to live at the capital?

Explain what the following quote means: “if men are naturally in a state of war, why do they always carry arms and why do they have keys to lock their doors? ”