HELP PLZ it do now

While I can't answer the second because I've forgotten what that is. I can answer the first one.

1. Black people must sit in the back of the bus so they can save the front for white people

2. White people and black people cannot use the same things. (Water fountains, bathrooms, etc.)

3. In some states, white people and black people could not marry each other due to Jim Crow laws.

Basically Jim Crow laws segregated African-Americans.

first, the romans stayed isolated because they had to defend their own territories from neighboring cities that were harassing them, like the etruscans. second, once the romans managed to defeat their neighbors, and started to expand their territory, they started to build roads and bridges. finally, now that the romans have covered their territory with roads functioning as highways, they could mobilize their legions faster to assemble larger military units in a specific place