Part II Reading Comprehension (Skimming and Scanning)(15 minutes)

　　Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions on Answer Sheet 1.For questions 1-7,choose the best answer from the four choices marked[A],[B],[C]and [D]. For questions 8-10,complete the sentences with the information given in the passage.

　　Will We Run Out of Water?

　　Picture a “ghost ship” sinking into the sand, left to rot on dry land by a receding sea. Then imagine dust storms sweeping up toxic pesticides and chemical fertilizers from the dry seabed and spewing them across towns and villages.

　　Seem like a scene from a movie about the end of the world? For people living near the Aral Sea in Central Asia, it’s all too real. Thirty years ago, government planners diverted the rivers that flow into the sea in order to irrigate (provide water for)farmland. As a result, the sea has shrunk to half its original size, stranding ships on dry land. The seawater has tripled in salt content and become polluted, killing all 24 native species of fish.

　　Similar large-scale efforts to redirect water in other parts of the world have also ended in ecological crisis, according to numerous environmental groups. But many countries continue to build massive dams and irrigation systems, even though such projects can create more problems than they fix. Why? People in many parts of the world are desperate for water, and more people will need more water in the next century.

　　“Growing populations will worsen problems with water,” says Peter H. Gleick, an environmental scientist at the Pacific Institute for studies in Development, Environment, and Security, a research organization in California. He fears that by the year 2025, as many as one-third of the world’s projected 8.3 billion people will suffer from water shortages.

　　Where Water Goes

　　Only 2.5 percent of all water on Earth is freshwater, water suitable for drinking and growing food, says Sandra Postel, director of the Global Water Policy Project in Amherst, Mass. Twothirds of this freshwater is locked in glaciers and ice caps. In fact, only a tiny percentage of freshwater is part of the water cycle, in which water evaporates and rises into the atmosphere, then condenses and falls back to Earth as precipitation(rain or snow).

　　Some precipitation runs off land to lakes and oceans, and some becomes groundwater, water that seeps into the earth. Much of this renewable freshwater ends up in remote places like the Amazon river basin in Brazil, where few people live. In fact, the world’s population has access to only 12,500 cubic kilometers of freshwater—about the amount of water in Lake Superior. And people use half of this amount already. “If water demand continues to climb rapidly,” says Postel, “there will be severe shortages and damage to the aquatic environment.”

　　Close to Home

　　Water woes may seem remote to people living in rich countries like the United States. But Americans could face serious water shortages, too especially in areas that rely on groundwater. Groundwater accumulates in aquifers, layers of sand and gravel that lie between soil and bedrock. (For every liter of surface water, more than 90 liters are hidden underground.)Although the United States has large aquifers, farmers, ranchers, and cities are tapping many of them for water faster than nature can replenish it. In northwest Texas, for example, over pumping has shrunk groundwater supplies by 25 percent, according to Postel.

　　Americans may face even more urgent problems from pollution. Drinking water in the United States is generally safe and meets high standards. Nevertheless, one in five Americans every day unknowingly drinks tap water contaminated with bacteria and chemical wastes, according to the Environmental Protection Agency. In Milwaukee, 400,000 people fell ill in 1993 after drinking tap water tainted with cryptosporidium, a microbe that causes fever, diarrhea and vomiting.

　　The Source

　　Where do contaminants come from? In developing countries, people dump raw sewage into the same streams and rivers from which they draw water for drinking and cooking; about 250 million people a year get sick from water borne diseases.

　　In developed countries, manufacturers use 100,000 chemical compounds to make a wide range of products. Toxic chemicals pollute water when released untreated into rivers and lakes. (Certain compounds, such as polychlorinated biphenyls, or PCBs, have been banned in the United States.)

　　But almost everyone contributes to water pollution. People often pour household cleaners, car antifreeze, and paint thinners down the drain; all of these contain hazardous chemicals. Scientists studying water in the San Francisco Bay reported in 1996 that 70 percent of the pollutants could be traced to household waste.

　　Farmers have been criticized for overusing herbicides and pesticides, chemicals that kill weeds and insects but that pollute water as well. Farmers also use nitrates, nitrogenrich fertilizer that help plants grow but that can wreak havoc on the environment. Nitrates are swept away by surface runoff to lakes and seas. Too many nitrates “over enrich” these bodies of water, encouraging the buildup of algae, or microscopic plants that live on the surface of the water. Algae deprive the water of oxygen that fish need to survive, at times choking off life in an entire body of water.

　　What’s the Solution?

　　Water expert Gleick advocates conservation and local solutions to water-related problems; governments, for instance, would be better off building small-scale dams rather than huge and disruptive projects like the one that ruined the Aral Sea.

　　“More than 1 billion people worldwide don’t have access to basic clean drinking water,” says Gleick. “There has to be a strong push on the part of everyone—governments and ordinary people—to make sure we have a resource so fundamental to life.”

　　1.What caused the Aral Sea to shrink?

　　[A]The rivers flowing into it have been diverted.

　　[B]Farmers used its water to irrigate their farmland.

　　[C]Government planners overpumped its water.

　　[D]High temperature made its water badly evaporate.

　　2.The construction of massive dams and irrigation projects .

　　[A]does more good than harm

　　[B]solves more problems than what they created

　　[C]does more harm than good

　　[D]brings more water to people than expected

　　3.The chief causes of water shortage include .

　　[A]population growth and water waste

　　[B]water pollution and dry weather

　　[C]water waste and pollution

　　[D]population growth and water pollution

　　4.Americans could suffer from greatly serious water shortages?

　　[A]living in rich areas

　　[B]living in big cities but poor condition

　　[C]depending on groundwater

　　[D]bearing high standards of safe drinking water in mind

　　5.What is the main pollutant in developed countries?

　　[A]Untreated toxic chemicals from manufacturers.

　　[B]Raw sewage into rivers and streams.

　　[C]Herbicides and pesticides used by farmers.

　　[D]Household cleaners poured down the drain.

　　6.How does algae make threats to life of a body of water?

　　[A]By covering the whole surface of the water.

　　[B]By competitively using oxygen life in water needs.

　　[C]By living more rapidly than other life in water .

　　[D]By releasing hazardous chemicals into water.

　　7.According to Gleick, who should be responsible for solving water-related problems?

　　[A]government and housewives.

　　[B]farmers and manufacturers.

　　[C]ordinary people and manufacturers.

　　[D]government and every person.

　　8. According to Peter H. Gleick, by the year 2025, as many as of the world’s people will suffer from water shortages.

　　9.Two thirds of the freshwater on Earth is locked in .

　　10.In developed countries, before toxic chemicals are released into rivers and lakes, they should be treated in order to avoid .

　　【全文翻译】

　　我们会陷入水资源枯竭的困境吗?

　　想象一只“幽灵船”沉入了沙土中，任其留在干旱的沙土中腐烂掉。再想象沙尘暴从干旱的海床上席卷起有毒的杀虫剂和化肥，呼啸着穿过城镇和村庄。

　　看起来像关于世界末日的电影中的一个场景?对于居住在中亚咸海附近的居民而言，这一切都是真实的。30年前，为了灌溉(提供水)农田，政府部门的规划专家们改道了引水入海的河流。结果，咸海缩小为原来的一半，船只也搁浅在干旱的沙土上。海水受到污染，其盐含量增到了三倍，导致24种土生土长的鱼类灭绝。

　　根据众多环保组织的调查，世界其他地方与此类似的大规模的改道努力也是以生态危机而告终的。尽管建造大坝和灌溉系统创造的问题要比它们解决的问题多，但是许多国家仍然继续这样的项目。为什么呢?世界许多地方的人都非常需要水;而且，随着人口的增长，下个世纪将有更多的人需要更多的水。

　　来自于太平洋发展、环境和安全研究所(the Pacific Institute for Studies in Development, Environment, and Security)的环境科学家Peter H. Gleick说，“不断增长的人口将会进一步恶化缺水问题”。该研究所是位于加利福尼亚的一个研究机构。他担心，到2025年，在83亿世界预计人口中，将有三分之一的人口面临缺水问题。

　　水去了哪里?

　　来自位于马塞诸塞州阿默斯特的全球水政策项目的Sandra Postel主任认为，地球上只有2.5%的水是适合饮用和种植食物的淡水，其中的三分之一属于冰川和冰盖。事实上，只有极小比例的淡水是水循环的一部分。在水循环中，水蒸发后上升到大气中，然后凝结并以降水的形式(雨或雪)回落到地球上。

　　一些降水流经陆地进入湖泊和海洋，另一些渗入地球变成地下水。大部分这样的再生淡水最后积聚在诸如巴西亚马逊河流域这样很少有人居住的偏远地方。事实上，世界人口能获得的淡水仅有12，500立方千米——相当于Superior湖的湖水量，其一半已为人类所使用。Postel 说，“如果水的需求量不断快速攀升，水资源将严重短缺，水环境将受到极大破坏。”

　　问题就在家门口

　　对于生活在像美国这样富裕国家的人来说，水危机似乎很遥远。但是美国人可能面临严重的缺水问题，尤其是那些依赖地下水的区域。地下水储存于地下含水层和位于泥土和岩床之间的沙石层中。(地球上的地表水与地下水的水量之比大约为1∶90。) 虽然美国富有含水层，农民、农场主和城市居民的用水速度超过了自然界水资源的再生速度。例如，根据Postel的调查，在西北部的得克萨斯州，超量的抽取使得地下水供应减少了25%。

　　美国人可能会面临更紧迫的污染问题。在美国，饮用水普遍安全，符合高标准要求。不过，据环境保护署的调查，每天有五分之一的美国人在不知不觉中饮用受到细菌和化学废物污染的自来水。1993年，密尔沃基有40万人因饮用受到隐孢子虫污染的自来水而患病。隐孢子虫是一种可引起高烧、腹泻和呕吐的微生物。

　　污染源

　　这些污染物从何而来呢?在发展中国家，人们把污水倒入他们从中获取饮用和烹饪水的同一小溪和河流中，每年大约有250万人感染水传播疾病。

　　在发达国家，制造商使用100,000种化合物来制造更多种类的产品。未经处理就被释放入河流和湖泊中的化学物质使水受到污染。(某些化合物，如多氯联苯，即PCBs，在美国已被禁用。)

　　但是，水污染几乎与每个人都有关。人们常常将清洁用品、汽车防冻剂、油漆稀释剂倒入下水道中，而所有这些用品都含有有害的化学物质。1996年，科学家们对旧金山海湾的水进行了研究，他们说，百分之七十的污染物可以追溯到家居废物。

　　除草剂和杀虫剂既可以杀死杂草和昆虫，也会污染水源，因此农民们一直因过量使用除草剂和杀虫剂而备受批评。农民们还使用可以促进植物生长的硝酸盐和富含氮的化肥，但是它们也会严重破坏环境。硝酸盐类物质会被地表径流冲刷入湖泊和海洋之中。过多的硝酸盐使得水域“超级富有”，从而造成水藻或水面微小植物的大量繁殖。藻类剥夺了鱼生存所必需的氧气，有时候会令整个水域中的生命窒息而亡。

　　解决的方法是什么呢?

　　水资源专家Gleick提倡保护水资源，通过因地制宜的方法来解决与水相关的问题。例如，政府最好建筑小规模的水坝，而不是像毁掉咸海那样具有破坏性的大水坝。

　　“全世界有超过10亿的人口缺乏基本的清洁饮用水，”Gleick说，“每个人——政府人员和普通人——都要付诸努力，确保我们有一个最基本的生活源泉。”

　　2016年下半年大学英语四级口语考试报名通知 2016年12月英语四级考试报名时间

　　【答案解析】

　　1.【解析】[A]属细节推断题。根据题干的意思，是什么原因造成咸海海水量的减少呢?本文的第二段提到了咸海的具体情况。所以根据题干中的核心词“Aral Sea”，并结合第二段的具体内容，可以将答案定位在该段的第二、三句话“...government planners diverted the rivers that flow into the sea in order to irrigate(provide water for)farmland. As a result, the sea has shrunk to half its original size,...”，这与A“The rivers flowing into it have been diverted”表示的“流入其的河流被改道”的意思相吻合。所以正确答案是A项。答案B和C均属于断章取义，偷换了句子中的部分内容，是迷惑项。答案D的内容按照常理来说，具有一定正确性，但文章并未提及，也是干扰项。

　　2.【解析】[C]属同义转换题。题干要求回答有关大坝建设和灌溉工程的情况，其中的“massive dams and irrigation”是核心词，定位于文章第三段。该段中的第二句话“...many countries continue to build massive dams and irrigation systems, even though such projects can create more problems than they fix”。这与C项意思“坏处多于好处”一致。所以正确答案是C。答案A和B的意思与原文相反;答案D在文中未提及，属于故意干扰项。

　　3.【解析】[D]属段落大意理解题。对于此类主旨大意题，可以先看题支中各个选项的区别和联系，然后结合自己对文章的理解来予以选择或者排除。本题要求回答缺水的主要原因是什么。对比四个选项，其中共有四种情况的不同组合：人口增长、水资源污染、水资源浪费和气候干燥。其中的“人口增长”在第三段结尾和第四段开头“Growing population will worsen problems with water”中提到过，属于缺水的主要原因之一;“水资源污染”在小标题“the source”下面分别从发展中国家、发达国家、个人和农民的角度作出重要说明，也是造成缺水的主要原因之一;“水资源浪费和气候干燥”在文中均未提及，所以正确答案是D。

　　4.【解析】[C]属同义转换题。根据题干中关键词“Americans”，可以定位在小标题“Close to home”下第一段的第二句话，“Americans could face serious water shortages, too especially in areas that rely on groundwater”，表明美国人，特别是依赖地下水的居民可能面临缺水问题，这与答案C的“depending on groundwater”意思一致，属于同义转换，所以答案选C。答案A、B、D都是文章中与题干内容相关的某句话的断章取义，属于干扰项。

　　5.【解析】[A]属细节推断题。根据题干中的关键词“pollutant”，可以将答案定位在小标题“The sources”之下，再根据“in developed countries”，可以定位于第二段前两句“In developed countries, ... Toxic chemicals pollute water when released untreated into rivers and lakes”。这与A“untreated toxic chemicals from manufacturers”完全吻合，所以答案是A。B是发展中国家水污染的主要来源，C和D分别说明的是农民和个人对水资源造成的污染，属于干扰项。

　　6.【解析】[B]属细节推断题。题干中的algae是关键词，将答案直接定位于小标题“The source”之下最后一段的最后一句，“Algae deprive the water of oxygen that fish need to survive, at times choking off life in an entire body of water”，这与B“与水域中的生物竞争氧气”相吻合，所以答案选B项。答案A是对文中部分内容的改写，与答案无关;C和D在文中均未提及。

　　7.【解析】[D]属细节推断题。题干中的“Gleick”和“solving waterrelated problems”是关键词，将答案定位在小标题“What’s the solution”之下最后一段的最后一句，“...says Gleick. ‘There has to be a strong push on the part of everyone—governments and ordinary people—to make sure we have a resource so fundamental to life’”，这与D“government and every person”意思一致，所以答案选D项。其他选项意思与文章不符。

　　8.【解析】one-third 解题依据为第四段最后一句话：He fears that by the year 2025, as many as one-third of the world’s projected 8.3 billion people will suffer from water shortages

　　9.【解析】glaciers and ice caps 解题依据为第五段第二句话：Twothirds of this freshwater is locked in glaciers and ice caps

　　10.【解析】water pollution 解题依据为第十段第二句话：Toxic chemicals pollute water when released untreated into rivers and lakes.