Both natural gas and biogas create emissions when burned, but far less than coal and oil do.
天然气和沼气燃烧时，都会产生二氧化碳，但是要比煤和石油少得多。
But the cleanliness of natural gas is largely based on its lower carbon dioxide emissions when burned.
但是天然气的清洁特性主要是基于其在燃烧时较低的二氧化碳排放量。
They also tend to produce poor-quality coal which generates relatively high levels of pollution when burned.
他们也倾向于生产劣质煤，这些煤在燃烧时产生相对高的污染水平。
Humanity's main fuel for eons was wood, which has a carbon-to-hydrogen ratio of 10 to 1 when burned; by comparison, that ratio is 2 to 1 for coal and 1 to 2 for oil.
千万年以来，人类的主要燃料是木头，燃烧木头的过程中，碳和氢的比率是10比1。相比较而言，煤在燃烧过程中这个比率是2比1，而石油的比率则是1比2。
Though cleaner than oil or coal, it does emit greenhouse gases when burned.
虽然，它比石油、煤更洁净，但燃烧天然气时会产生温室气体。
Some can release harmful and poisonous things when burned, and many end up in the sea and can kill some marine animals that mistake them for food.
一些塑料袋焚烧时还会散发出有害和有毒的物质，许多塑料袋最终被弃入大海，一些海洋动物误将它们当成食物吞下，因而丧生。
This result reinforced Lavoisier's findings in 1772 when he discovered that both phosphorus and sulfur when burned increase in weight section 25.5
该结果强化了拉瓦锡在1772年的发现：那时，他发现磷和硫在燃烧中其重量是增加的（第25.5节）。
A plant is said to be carbon neutral if the carbon dioxide that it absorbs while alive is the same as the carbon dioxide it emits when burned as a fuel.
据说如果植物在生长时所吸收的二氧化碳量等同于该植物被作为燃料燃烧时所释放的二氧化碳量时，那么这株植物就是碳中和了。
Later, the people found that the bamboo could make a crackling sound when burned. In time, the noise of crackling bamboo was replaced with bang of firecrackers.
后来，人们发现燃烧竹子能发出噼啪的爆裂声，再后来，燃放爆竹取代了燃烧竹子。
Melamine is a trimer of cyanamide. It contains 66% nitrogen (by mass) and provides fire retardant properties to resin formulas by releasing nitrogen when burned or charred.
三聚氰胺是氨腈的三聚体。它含66%的氮（质量）并在燃烧或焦化时通过释放氮气为树脂产品提供阻燃特性。
When burned, waste oil biodiesel is also generally cleaner for the air than diesel, emitting lower levels of pollutants, including particulate matter.
废油制成的生物柴油燃烧后造成的空气污染通常也比柴油要小，包括颗粒物在内的污染物的排放量更少。
When burned, waste oil biodiesel is also generally cleaner for the air than diesel, emitting lower levels of pollutants, including particulate matter.
废油制成的生物柴油燃烧后造成的空气污染通常也比柴油要小，包括颗粒物在内的污染物的排放量更少。
应用推荐