煤是一種化石燃料，是史前植被的蝕變遺跡，最初堆積在沼澤和泥炭沼澤中。我們今天從煤中獲得的能量來(lái)自數(shù)百萬(wàn)年前植物從太陽(yáng)中吸收的能量。

Coal is a fossil fuel and is the altered remains of prehistoric vegetation that originally accumulated in swamps and peat bogs. The energy we get from coal today comes from the energy that plants absorbed from the sun millions of years ago.