What type of unclassified material should always be marked

Look at the map of cities in the united states at the turn of the twentish century what impact did railroads have on cities across the united states at the turn of the twentish century

What is a common factor all nonprofit businesses share? they pay no income tax. they have no capital. they are national in scope. they perform charitable acts.

In exchange for land, a knight agrees to be a sort of sub-vassal to a vassal. this agreement was known as: investiture homage tyranny subinfeudation