In Earth's earliest atmosphere, methane and carbon dioxide occurred at much higher levels than at present-a circumstance that was favorable for early life.(在地球最早的大氣層中，甲烷和二氧化碳的含量比現(xiàn)在要高得多，這對(duì)早期生命來說是有利的。)

Although the system would consume energy, it would return energy to the grid via methane generation from composting nonedible parts of plants.(盡管該系統(tǒng)會(huì)消耗能源，但它會(huì)通過從植物不可食用的部分堆肥產(chǎn)生的沼氣將能源回饋給電網(wǎng)。)

Many environmental experts now believe that methane is more responsible for global warming than carbon dioxide.(許多環(huán)境專家現(xiàn)在認(rèn)為，甲烷比二氧化碳對(duì)全球變暖負(fù)有更大的責(zé)任。)

When our Sun later became hotter, the continued removal of atmospheric carbon dioxide and methane by early bacteria kept Earth's climate from becoming too hot to sustain life.(當(dāng)我們的太陽后來溫度變得更高時(shí)，早期細(xì)菌持續(xù)清除大氣中的二氧化碳和甲烷，使地球的氣候不至于變得太熱而無法維持生命的存在。)

Therefore, the methane now emitted from open landfills should instead be burned to produce electricity.(因此，現(xiàn)在從露天垃圾填埋場(chǎng)排放的甲烷應(yīng)該被用來發(fā)電。)

The large amount of methane contained in the atmosphere surrounding Neptune stained it blue.(圍繞海王星的氣層內(nèi)所含大量甲烷將它染成了藍(lán)色。)

Other ancient bacteria consumed methane, greatly reducing its amount in the atmosphere.(其他古代細(xì)菌消耗甲烷，大大減少了甲烷在大氣中的含量。)

Methane and propane are alkanes.(甲烷和丙烷是烷烴。)

Far from the sun, in the outer solar system, beyond Jupiter's orbit, temperatures are low enough to permit ices to form out of water and out of gases like methane and carbon dioxide.(在遠(yuǎn)離太陽的外太陽系，在木星軌道之外，溫度低到足以使冰從水以及甲烷和二氧化碳等氣體中形成。)

The burning of methane generates carbon dioxide that is released into the atmosphere.(燃燒甲烷產(chǎn)生二氧化碳，然后釋放到大氣中。)