Nitrogen-oxide emissions during the cruising portions of the flight fell by around a quarter.(飞行中巡航部分的氮氧化物的排放量下降了四分之一左右。)
Agricultural run-off and pollution from power plants are adding extra nitrogen to many bogs in North America.(农业排水和来自发电厂的污染给北美的许多沼泽增加了额外的氮。)
Since nitrogen is four fifths of the air we breathe, they are surprisingly optimistic about raising the temperature on Mars and believe it could be done in hundred years.(由于氮占我们呼吸的空气的五分之四，他们对提高火星的温度持惊人的乐观态度，相信这可以在一百年内完成。)
A third is certain basic chemicals such as carbon, oxygen and nitrogen.(第三种是某些基本的化学物质，如碳、氧和氮。)
You said that the nitrogen cycle is also an important nutrient cycle.(你说了，氮循环也是一个重要的营养循环。)
A century earlier, Henry Cavendish had noted the existence of a residual gas when oxygen and nitrogen are removed from air, but its importance had not been realized.(早在一个世纪以前，亨利·卡文迪什就注意到：当氧和氮从空气中除去时，会有残余气体存在；但人们还没有认识到这些残余气体的重要性。)
Even nitrogen, which is a gas in its elemental state, is normally absorbed from the soil as nitrate ions.(即使是元素状态为气体的氮，也通常作为硝酸根离子从土壤中被吸收。)
Soils are most commonly deficient in nitrogen and phosphorus.(土壤最经常缺乏氮和磷。)
Plankton generally thrive in areas of the ocean with sufficient concentrations of certain nitrogen compounds near the surface, where plankton live.(浮游生物通常在海洋表面附近某些含氮化合物浓度足够高的区域大量繁殖，而海洋表面正是浮游生物生存的地方。)
The faeces contain nitrogen which fertilizes the soil.(排泄物含有肥沃土壤的氮。)
