What factors would or circumstances would have made conquering and ruling such a vast empire difficult?

Some factors or circumstances that would have made conquering and ruling such a vast empire was, Getting past guards and enemies to try  to conquer,since the empire was so vast,you would have to deal with battling hundreds or thousands of people,putting your life and others in danger.

well, paralell is parallel. i am providing links to .

hope this !

a series circuit is one with all the loads in a row. there is only one path for the electricity to flow. if this circuit was a string of light bulbs, and one blew out, the remaining bulbs would turn off.

unlike in series circuits, a charge in a parallel circuit encounters a single voltage drop during its path through the external circuit. the current through a given branch can be predicted using the ohm's law equation and the voltage drop across the resistor and the resistance of the resistor.

a parallel circuit has certain characteristics and basic rules: a parallel circuit has two or more paths for current to flow through. voltage is the same across each component of the parallel circuit.

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