The earliest of civilizations were based around river valleys. This allowed them to irrigate fresh water to their crops allowing for better farming and therefore, bigger and better civilizations.
Worldwide, the most widely used renewable energy resource is to plant materials and animal waste used as a fuel.
Answer will be bolded
the sun/radiation (sorta)/ fusion/(yea pretty much the sun)
$15 by 2.60 times 4.5 is 11.7 and 11.7 plus 3.30 is 15
