What information can we learn from about prehistoric (time before writing) society that can help us today?

We can learn many helpful things from prehistoric societies. In fact, anthropologist and historians are often interested in these socities for this very reason.

Explanation:

A helpful information is diet: most prehistoric societies were hunter-gatherers (they did not know agriculture), and for this reason, their diets were very different from the diets of following periods. Some scholars have even said that prehistoric diets were healthier than the diets of agricultural societies.

Another helpful information can be found from archeological evidence: things such as cultural artefacts can shed light on prehistoric culture, and help develop theories about the origin of human cultural institutions, theories that can helps us understand better the modern world.

i'd assume india mainly because of how isolated japan was.   plus it is a whole china away.

a. by accepting the election of president abraham lincoln in 1860 and convincing other southern states to do the same