Are there dead zones in the ocean? Find out on this Moment of Science.
　　Well, as if we needed one more reason to get our environmental act together, a recent U.N. report warns that the number and size of dead zones in the ocean is increasing.
　　Dead zones are regions of oxygen-deprived water, where nothing can live. They’re caused by an excess of nutrients–usually nitrogen(氮)–released into the water. When sewage, farm fertilizers, and emissions from vehicles and factories get washed into the ocean, you get what experts call a “nitrogen cascade(氮容器)”. Tiny free- floating organisms known as plankton(浮游生物) feed on all that untreated nitrogen, and multiply to such an extent that they (1)deplete the oxygen supply in the water.
　　While fish may be able to swim away and avoid (2)suffocation, slower-moving and (3)bottom-dwelling creatures like lobsters(龙虾), clams(蛤蚌), and oysters(牡蛎) often can’t. Also, the ocean might be a large place, but right now there are 146 known dead zones, some of which span tens of thousands of square miles. One of the worst is where the Mississippi River (4)drains into the Gulf of Mexico, and dumps fertilizer (5)runoff from the Midwest.
　　Oh,no.Is there anything we can do? We can reduce nitrogen emissions from cars and factories, and implement better sewage treatment. We can plant new forest and grasslands to (6)soak up extra nitrogen and keep it out of the water. And we can develop alternative energy sources(替代能源) that aren’t based on burning fossil fuels(化石燃料).
　　译文：
　　如果我们需要一个理由一起进行环保行动，那么这个理由就是联合国最近的发布的一个报告警告说海洋死区的数量在不断增多，面积在不断增大。
　　海洋死区是指海水中的氧气被消耗减少，以致没有东西能够生存。它们是由排入水中的过剩的营养物质引起的-这种物质常常是氮。当污水，农田肥料，以及车辆和工厂的排放物被冲刷入海中时，就形成了专家所谓的“氮容器”。像浮游生物这些自由浮动的微小生物就是以未经处理的氮为食。它们繁殖到了如此的程度，以致于耗尽了水中供应的氧气。
　　尽管鱼可以游走避免窒息，但是那些缓慢移动和底栖的生物，列如：龙虾，蛤蚌，和牡蛎却不行。或许海洋是一个广阔的地方，但是目前已知的海洋死区已有146个，其中一些跨度数万平方英里。最严重的地方之一是密西西比河流入墨西哥湾的地方，这里倾倒着从中西部流失过来的肥料。
　　噢，不。有没有什么我们可以做的呢?我们可以减少汽车和工厂氮的排放量，并且实施更好的污水治理方法，种植新的森林和草地来吸收多余的氮，并使氮远离水源。我们还可以开发不以化石燃料燃烧为基础的替代能源。
　　 Notes:
　　 (1)deplete [di’pli:t] vt.耗尽，用尽;使衰竭，使空虚
　　 The fire had depleted the game in the forest.
　　那场大火使森林里的鸟兽濒临绝迹。
　　 (2)suffocation [,sʌfə’keiʃən] n.窒息;闷死
　　 A target that makes her save is immune to suffocation from that elemental for 24 hours.
　　豁免成功的目标在24小时内免疫这个火元素造成的窒息效果。
　　 (3)bottom-dwelling 底栖生物
　　 marine eellike mostly bottom-dwelling fishes of northern seas.
　　北部海洋中大多数底栖的似鳗海鱼。
　　 (4)drain into 流入，排入，泄入
　　 The river drains into the sea.
　　河流向大海。
　　 (5)runoff n.径流;决赛;流走的东西 adj.决胜的
　　 So, it is practical to use the sequential clustering and Markov model to forecast the river runoff.
　　这说明运用马尔可夫模型进行河径流量的丰枯状态预报是有效可行的。
　　 (6)soak up v.吸收
　　 Soak the spilt tea up with a cloth.
　　用块布把洒了的茶水吸干。