sentences: fossil fuels are a nonrenewable resource & fossil fuels / fossils forming occurs over a period of 300000000 years which is considered a very long time to a human ->  nonrenewable resources forming occurs over a period of 300000000 years which is considered a very long time to a human  two million or more years means millions of years & 300000000 years equals three hundred million years ->  300000000 years means millions of years  nonrenewable resources forming occurs over a period of 300000000 years which is considered a very long time to a human & 300000000 years means millions of years ->  nonrenewable resources forming occurs over a period of millions of years  years are a kind of unit for measuring time & how long something takes is a kind of measurement of time ->  how many years something takes is a kind of measurement of time  how many years something takes is a kind of measurement of time & a period is a kind of measurement of time ->  how many years something takes is a kind of period  nonrenewable resources forming occurs over a period of millions of years & how many years something takes is a kind of period -> nonrenewable resources forming can take millions of years