How many people are in the world

What is one reason the united states had a two party system

Historians are concerned with the accuracy of their writings and readings but are also aware of the inability of authors to know every angle of every story biases, perspectives, beliefs, and a variety of other differences history being told by one person at a time no one being totally accurate, as hard as we try really need on this, and you^^

What emperor was given credit for having the aqueducts built