There military strength, there economy must be stable, and they must have a strong government
The first word is Sink and the second is denser
Rome gets its water from lake Bracciano and the aqueducts, which supplied fresh water to public baths and for drinking water, in large cities across the empire, and set a standard of engineering that was not surpassed for more than a thousand years.
The most abundant fossil fuel is coal... Coal isn't only our most abundant fossil fuel,it's also the one with perhaps the longest history. The U.S. has more coal reserves than any other country in the world. In fact, one-fourth of the all the known coal in the world is in the U.S.