1、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。)
2、Agricultural run-off and pollution from power plants are adding extranitrogen 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。)
3、Sincenitrogen 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。)
4、A third is certain basic chemicals such as carbon, oxygen andnitrogen.(第三种是某些基本的化学物质，如碳、氧和氮。)
5、You said that thenitrogen cycle is also an important nutrient cycle.(你说了，氮循环也是一个重要的营养循环。)
6、A century earlier, Henry Cavendish had noted the existence of a residual gas when oxygen andnitrogen 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。)
7、Evennitrogen, 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。)
8、Soils are most commonly deficient innitrogen and phosphorus.(土壤最经常缺乏氮和磷。)
9、Plankton generally thrive in areas of the ocean with sufficient concentrations of certainnitrogen 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。)
10、The faeces containnitrogen which fertilizes the soil.(排泄物含有肥沃土壤的氮。)
11、There's just not a substantial amount of it there, like there is withnitrogen, it's a very minimal quantity.(在那里它没有很大的量，就像氮一样，它的含量非常少。)
12、nitrogen is one of the byproducts.(氮就是其中的一个副产品。)
13、Before letting its leaves go, the tree dismantles their chlorophyll molecules and ships their valuablenitrogen back into the twigs.(在树叶凋落之前，树会分解叶绿素分子，把有用的氮运回树枝中。)
14、Carnivorous plants are so finely tuned to low levels ofnitrogen that this extra fertilizer is overloading their systems, and they eventually burn themselves out and die.(肉食性植物能很好地适应低浓度氮，因此这些额外的肥料会使它们的系统负担过重，最终它们会被压垮并死亡。)
15、nitrogen dioxide is a pollutant emitted by automobiles.(二氧化氮是汽车排放的一种污染物。)
16、These pollutants are called aerosols and they include soot as well as compounds ofnitrogen and sulfur and other stuff into the air.(这些污染物被称为气溶胶，它们包括煤烟以及空气中氮、硫和其他物质的混合物。)
17、Carnivorous plants instead drawnitrogen, phosphorus, and other critical nutrients from their prey in order to build light-harvesting enzymes.(相反，食肉植物从它们的猎物那里吸收氮、磷和其他重要的营养物质，以制造聚光酶。)
18、nitrogen is an unstable element.(氮是一种不稳定的元素。)
19、Compounds ofnitrogen and sulphur dioxide should be particularly closely watched.(应特别密切注意氮和二氧化硫的化合物。)
20、Horse waste is rich in phosphorus and alsonitrogen compared to normal soil.(和普通土壤相比，马粪更富含磷和氮。)
21、The major difference is that Allende is depleted in the most volatile elements, like hydrogen, carbon, oxygen,nitrogen, and the noble gases, relative to the Sun.(主要的差别是，相比于太阳，阿连德陨石缺失了大部分的挥发性元素，例如氢、碳、氧、氮和稀有气体。)
22、The conditions for acquiring and retaining a thicknitrogen atmosphere are now readily understood.(现在很容易了解获得和保持厚氮大气的条件。)
23、Now, researchers have a way for people to measure how muchnitrogen pollution they produce—theirnitrogen footprint.(如今，研究人员为人们提供了一种测量个人产生的氮污染量的办法——他们的氮足迹。)
24、The poor soil of bogs, for example, offers littlenitrogen and phosphorus, so carnivorous plants enjoy an advantage over plants that obtain these nutrients by more conventional means.(例如，沼泽贫瘠的土壤提供的氮和磷很少，所以肉食植物比那些通过更传统的方式获得这些营养的植物更有优势。)
25、The tanker was carrying liquidnitrogen.(油轮那时正在运送液态氮。)
26、The three most important nutrient recycles are thenitrogen cycle, the carbon cycle and the one we are going to talk about today, the Phosphorus cycle.(这三种最重要的营养循环包括氮循环、碳循环和我们今天要讲的磷循环。)
27、We look at soil chemistry—for example, how muchnitrogen or magnesium there is in the soil in one spot—and we compare it with the chemistry of the soil a short distance away.(我们会观察土壤的化学性质——比如某个地方的土壤里有多少氮或者镁——然后与附近土壤的化学性质作比较。)
28、The plant requiresnitrogen in order to make proteins.(植物需要氮以制造蛋白质。)
29、Some areas, though rich in thesenitrogen compounds, have few plankton.(有些地区虽然富含氮化合物，但浮游生物却很少。)
30、Above all, they will have to discover how muchnitrogen it possesses.(最重要的是，他们必须搞清楚这里面含有多少氮。)
