PAHs are a group of chemicals that are formed the incomplete burning of coal, oil and gas, garbage, or other organic substances.

多环芳烃是一组化学物质，他们是由未经完全燃烧的煤。油和气。垃圾。或是其它有机物质形成的。

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And the particles released by the incomplete burning of fossil fuels give rise to urban smog, which cause many respiratory diseases, for instance, asthma.

化石能源的不完全燃烧会释放微尘，造成城市雾，这会引起很多呼吸系统疾病，比如哮喘。

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Aiming at the facts of low temperature, rare oxygen and low-pressure, ameliorates phenomena of burner igniting difficulty , unsteady flame and incomplete burning by improving on burner's parts.

针对高原地区低温、缺氧、气压低的客观现实，通过对轻油燃烧器结构的改进，解决了燃烧器点火困难、火焰不稳定及燃烧不完全问题；

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The academics advocate concentrating first on short-term fixes for greenhouse gases or other warming agents, such as black carbon - particles emitted from the incomplete burning of fossil fuels, principally in diesel engines and wood stoves.

BBC: Academics urge radical new approach to climate change