求翻譯…… 當(dāng)非化石的有機物質(zhì)經(jīng)過厭氧腐爛時，會產(chǎn)生富含甲烷的氣體，這種氣體就被稱作生物氣（沼氣）

【專家解說】：When non fossil organic matter through the anaerobic decay, will produce methane rich gas,this gas is called biogas (methane). The source of biogenic gas include forest and grasslandbetween the marsh and landfill, in sewer sludge, manure, produced by bacteria in anaerobicdecomposition. Biogas also includes flatulence (for example: fart), gastrointestinal gas mostoften from domestic animals such as cattle and sheep.