In 1880, coal powered a steam engine attached to the world's first
electric generator. Thomas Edison's plant in New York City provided the
first electric light to Wall Street financiers and the New York Times.Only a year later, the world's first hydroelectric plant went on-line in Appleton, Wisconsin.By the late 1800s, a new form of fuel was catching on: petroleum.With the low-cost automobile and the spread of electricity, our
society's energy use changed forever. Power plants became larger and
larger, until we had massive coal plants and hydroelectric dams. Power
lines extended hundreds of miles between cities, bringing electricity to
rural areas during the Great Depression.(this is just a brief description)
The main mechanism through which the layering happened is gravity: it pulled the heavier, denser material to the center, leaving the less dense material on the surface.
The material that was on the outside cooled quicker, but this was the result, not the cause.
The answer is
<span>2) Gravity caused more-dense material to move toward the center of each planet.</span>
Its spread mainly because of the pest rats and also fleas
Answer:
To calculate the RNI, demographers subtract the death rate (number of deaths per 1,000 people/year) from the birth rate (number of birth per 1,000 people/year) and convert the answer to a percentage.
Equation for Rate of Natural Increase (RNI):
(BirthRate/1,000) – (DeathRate/1000) = (BR-DR)/1000 = RNI %
Hope it helps!
