関連ワード:  why are coal natural gas and oil called fossil fuels    why are coal oil and natural gas called fossil fuels quizlet    why are crude oil natural gas and coal called fossil fuels    why are coal mineral oil and natural gas called fossil fuels class 8    explain why coal oil and natural gas are called fossil fuels    why are fossil fuels like coal oil and natural gas called nonrenewable resources    why are oil and gas called fossil fuels  
結果 : why are coal natural gas and oil called fossil fuels