Historians must look at the age of the evidence itself, they must also look at whether it can be corroborated by other pieces of historical evidence and that the source of the evidence is reliable.
Answer:
His three basic teachings: the need for justice, morality, and service to others.
Explanation:
Jesus spread: love God, love your neighbor and yourself, forgeive those who have wronged you.
(I would assume that any of your choices not including any of these would be a teaching he didn't spread. Sorry I didn't have much to go off to give an exact answer.)
Americans adopted representative governments with democratic principles that allowed each person to have a voice in the decisions about their country.