What is this and what doe they do and create Locks

Compare how one's social status affect his or her opportunities in ancient greece and rome?

In the mid-1800s, native americans who had lived in the westtraded their manufactured goods with settlers.were able to resist diseases carried by settlers.offered their services as guides to settlers.prevented settlers from moving onto their territory.

What event brought the us into wwii? what conflicts happened after the us entered the war? i know the first part of this question, i need with the second part.