Making Every Drop Count
A The history of human civilisation is entwined with the history of the ways we have learned to manipulate water resources. As towns gradually expanded, water was brought from increasingly remote sources, leading to sophisticated engineering efforts such as dams and aqueducts. At the height of the Roman Empire, nine major systems, with an innovative layout of pipes and well-built sewers, supplied the occupants of Rome with as much water per person as is provided in many parts of the industrial world today.
B During the industrial revolution and population explosion of the 19th and 20th centuries, the demand for water rose dramatically. Unprecedented construction of tens of thousands of monumental engineering projects designed to control floods, protect clean water supplies, and provide water for irrigation and hydropower brought great benefits to hundreds of millions of people. Food production has kept pace with soaring populations mainly because of the expansion of artificial irrigation systems that make possible the growth of 40 % of the world's food. Nearly one fifth of all the electricity generated worldwide is produced by turbines spun by the power of falling water.
C Yet there is a dark side to this picture: despite our progress, half of the world's population still suffers, with water services inferior to those available to the ancient Greeks and Romans. As the United Nations report on access to water reiterated in November 2001, more than one billion people lack access to clean drinking water; some two and a half billion do not have adequate sanitation services. Preventable water-related diseases kill an estimated 10,000 to 20,000 children every day, and the latest evidence suggests that we are falling behind in efforts to solve these problems.
D The consequences of our water policies extend beyond jeopardising human health. Tens of millions of people have been forced to move from their homes - often with little warning or compensation - to make way for the reservoirs behind dams. More than 20% of all fresh water fish species are now threatened or endangered because dams and water withdrawals have destroyed the free-flowing river ecosystems where they thrive. Certain irrigation practices degrade soil quality and reduce agricultural productivity. Groundwater aquifers*are being pumped down faster than they are naturally replenished in parts of India, China, the USA and elsewhere. And disputes over shared water resources have led to violence and continue to raise local, national and even international tensions.
E At the outset of the new millennium, however, the way resource planners think about water is beginning to change. The focus is slowly shifting back to the provision of basic human and environmental needs as top priority -ensuring 'some for all, 'instead of 'more for some'. Some water experts are now demanding that existing infrastructure be used in smarter ways rather than building new facilities, which is increasingly considered the option of last, not first, resort. This shift in philosophy has not been universally accepted, and it comes with strong opposition from some established water organisations. Nevertheless, it may be the only way to address successfully the pressing problems of providing everyone with clean water to drink, adequate water to grow food and a life free from preventable water-related illness.
F Fortunately -and unexpectedly - the demand for water is not rising as rapidly as some predicted. As a result, the pressure to build new water infrastructures has diminished over the past two decades. Although population, industrial output and economic productivity have continued to soar in developed nations, the rate at which people withdraw water from aquifers, rivers and lakes has slowed. And in a few parts of the world, demand has actually fallen.
G What explains this remarkable turn of events? Two factors: people have figured out how to use water more efficiently, and communities are rethinking their priorities for water use. Throughout the first three-quarters of the 20th century, the quantity of freshwater consumed per person doubled on average; in the USA, water withdrawals increased tenfold while the population quadrupled. But since 1980, the amount of water consumed per person has actually decreased, thanks to a range of new technologies that help to conserve water in homes and industry In 1965, for instance, Japan used approximately 13 million gallons* of water to produce $1 million of commercial output; by 1989 this had dropped to 3.5 million gallons (even accounting for inflation) - almost a quadrupling of water productivity. In the USA, water withdrawals have fallen by more than 20 % from their peak in 1980.
H On the other hand, dams, aqueducts and other kinds of infrastructure will still have to be built, particularly in developing countries where basic human needs have not been met. But such projects must be built to higher specifications and with more accountability to local people and their environment than in the past. And even in regions where new projects seem warranted, we must find ways to meet demands with fewer resources, respecting ecological criteria and to a smaller budget.
• underground stores of water
• 1 gallon: 4.546 litres
Reading Passage 2 has seven paragraphs, A-H.
Choose the correct heading for paragraphs A and C-H from the list of headings below.
Write the correct number, i-xi, in boxes 14-20 on your answer sheet.
段落主题句：第1句
题解：从写作角度看，一篇学术性文章如果讨论一个问题， 通常按照“提出问题，分析问题，解决问题”的顺序来展开文章。提出问题部分通常会出现描写现象，或者阐述概念等。本文讨论的是水利工程带来的问题，大致会在文章首先简述水利工程，并按照发展顺序由古而今描写。第1句提到人类取水由来已久，第2 句详细展开说明，第3句出现具体地名，乃是例子。 选项xi中“water supplies”与文中“manipulate water resources”对应，同时“ancient”与“history”对应；而“描写”又应当出现在文章前部。本题答案为xi。
段落主题句：half of the world’s population still suffers
题解：本段第1 句是主题句。第2 句和第3 句中均出现具体数字，是用来支撑观点的论据。主题句中关键词是“population”和“suffers”。与之相关的选项只有vii 和viii，但是viii 中的“人口扩张”文中并未提到，故非答案。vii 中“health”与“suffers”对应，同时第2， 3 句中提到的“安全饮用水”，“卫生设施”和“与水有关的疾病”都体现了“suffers”的具体细节。故选 项vii 是正确答案。
注意：本题容易误选viii，但选项中出现“population” 是文章原词，没有同义替换，应该警惕。同时，在做下一道题阅读下一段时，会直接在该段主题句看到承 上词“beyond jeopardizing human health”，证明上段主要说明与“人类健康”有关。
段落主题句：第1句
题解：第1 句为主题句，其关键词为“consequences”，与选项v 中“effects”对应。后面句子详细以“水库移民”“淡水生物濒危”“土壤退化”“地下水抽取速度过快”说明水政不当带来的环境影响。本题答案为v。
段落主题句：第1 句
题解：“resource planners”与“scientists”对应“，revision”与“shift” 对应，“policy”与“the way… think about water”对应。 第2 句交代变化的方向，第3 句交代科学家提出的变化的具体内容。第4 句交代此变化的现状，第5 句交代趋势和重要性。每一句都是围绕科学家所提出的水政 变化展开。本题答案为i。
段落主题句：第1句
题解：文章中“demand for water”并未变化，“not rising as rapidly as some predicted”对应选项ix 中“surprising downward trend”。本题答案为ix。
段落主题句：第1、2句
题解：文章中出现问句时，后面的回答通常是作者的观点。且其他句子中出现具体地名和数字，是用来证明主题句的论据。其中问句中“what explains”对应“explanation”，“turn of events”在上段已经提过，对应选项ii 中“reduced water use”。本题答案为ii。
段落主题句：第2句
题解：当文章中出现表示强转折含义的关系词时，表示“但是”意义后面的内容通常比较重要。主题句中关键词“higher specifications and with more accountability”是选项x 中“raise standards”的具体体现。 注意：类似强转折词有but，yet，however，nevertheless 等。本题答案为x。