How many spaces are required between punctuation?

The graph shows the price of a good compared to the quantity demanded and the quantity supplied. on this graph, the bottom horizontal line represents an ineffective price floor set above equilibrium. an effective price floor set below equilibrium. an ineffective price ceiling set above equilibrium. an effective price ceiling set below equilibrium.

American s often refer to a country that is not the u.s as a a( domestic), or b(foreign)

How did the nazis lead germany to war in europe and, with their collaborators, kill millions—including systematically murdering six million jewish people?