在通风不良的住所，室内烟雾可超过可接受的微小颗粒含量，比室外空气高100倍。
In poorly ventilated dwellings, indoor smoke can exceed acceptable levels for small particles in outdoor air 100-fold.
基于各种努力，与2000年相比，北京市空气中的硫化物含量减少了近一半，工业烟尘排放量则减少了三份之二。
Because of that and other changes, Beijing’s sulfur emissions have been cut almost in half compared with 2000, and industrial dust has decreased by two-thirds.
氨气和硫化氢气都是有害气体，而且比二氧化碳的危害更大，特别是氨气在空气中的含量要限制在百万分之十五以下。
Ammonia gas and hydrogen sulfide is harmful gas, and more harmful than carbon dioxide, especially ammonia in the air to limit the content below fifteen over one million.
二氧化碳是空气的含量较小但很重要的组成成分，体积比平均约为0.03%或300ppm。
Carbon dioxide is a minor but important constituent of the atmosphere, averaging about 0.03% or 300 PPM by volume.
二氧化碳是空气的含量较小但很重要的组成成分，体积比平均约为0.03%或300ppm。
Carbon dioxide is a minor but important constituent of the atmosphere, averaging about 0.03% or 300 PPM by volume.
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