Religious and ethnical problems.
It was one of the largest empires of the world with many different ethnicities. The problem was to unite people under one rule.
Another problem was communication. It was hard to transfer knowledge and news to all parts of the empire because it was too large.
Answer: Gneiss
Explanation: Gneiss is a metamorphic rock formed from shale at very high temperature and pressure condition. They exhibit a preferred alignment or orientation of platy minerals called foliation. They are coarse grained and exhibit gneissose banding. They are formed from highest grade regional metamorphism with temperature between 450 - 600 degree celcius and pressure between 800 - 1000 mega pascal. They generally occur in cores of fold mountain belts where mountain ranges have been eroded.
Carbon neutral is a term used to describe carbon-based fuel that when burned will not increase carbon dioxide in the atmosphere. these fuels neither contribute to nor reduce the amount carbon so the carbon will remain the same.
so I think carbon neutral is good for the environment but not us humans
Answer: Kerogen
Explanation: a Kerogen is an organic substances that helps to permeate (has pores which allow the inflow and outflow of certain substances like air or watee)oil shells, Kerogen has not net been converted to oil.Kerogens are waxy in nature with complex structures,Kerogens can not be extracted using organic Kerogens also contain Sulfur and Nitrogen. Kerogen contains Hydrocarbons in the form of paraffin which disolves under high temperatures and pressure into substances similar to petroleum.
Hot hot magma at least i think
