『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 29 Passage 3阅读练习：The term “by then” in the passage refers to真题题目及答案解析，TPO/Official 29 Passage 3阅读原文范文音频翻译

托福TPO/Official 29 Passage 3阅读原文The term “by then” in the passage refers to题目答案及解析-新东方托福官方网校手机版

流水是最早被用来减少人类和动物的工作量的能源之一。

Moving water was one of the earliest energy sources to be harnessed to reduce the workload of people and animals.

没有人知道水车是什么时候发明的，但灌溉系统至少在5000年前就已经存在了，而且似乎最早的水力发电装置是一种水车：戽水车，可以用附在罐子里的水来灌溉。

No one knows exactly when the waterwheel was invented, but irrigation systems existed at least 5,000 years ago, and it seems probable that the earliest waterpower device was the noria, a waterwheel that raised water for irrigation in attached jars.

这种装置似乎不晚于公元前5世纪就已经逐渐发展出来了，也许是在中东和远东的不同的地区独立发展出来的。

This device appears to have evolved no later than the fifth century B.C., perhaps independently in different regions of the Middle and Far East.

最早的水力磨坊可能是用来磨玉米的垂直轴磨坊，被称为北欧或希腊磨坊，它们似乎出现在公元前1世纪或2世纪的中东，几个世纪后出现在斯堪的纳维亚。

The earliest waterpower mills were probably vertical-axis mills for grinding corn, known as Norse or Greek mills, which seem to have appeared during the first or second century B.C. in the Middle East and a few centuries later in Scandinavia.

在接下来的几个世纪里，在整个罗马帝国以及在中东和北欧边界以外的地方，建造了越来越复杂的水力磨坊。

In the following centuries, increasingly sophisticated waterpower mills were built throughout the Roman Empire and beyond its boundaries in the Middle East and northern Europe.

在英格兰，撒克逊人被认为同时使用水平轴和垂直轴的轮子。

In England, the Saxons are thought to have used both horizontal- and vertical-axis wheels.

第一个有记载的英国磨坊出现在8世纪，但3个世纪后，大约有5000个磨坊被记录在案，这表明任何规模的殖民地都有自己的磨坊。

The first documented English mill was in the eighth century, but three centuries later about 5,000 were recorded, suggesting that every settlement of any size had its mill.

提水和磨玉米绝不是水力磨坊的唯一用途，在接下来的几个世纪里，水力发电的应用与采矿、炼铁、造纸、羊毛和棉花等工业技术的发展同步。

Raising water and grinding corn were by no means the only uses of the waterpower mill, and during the following centuries, the applications of waterpower kept pace with the developing technologies of mining, iron working, paper making, and the wool and cotton industries.

水是机械动力的主要来源，到17世纪末，仅英格兰就有大约2万个磨坊在运转。

Water was the main source of mechanical power, and by the end of the seventeenth century, England alone is thought to have had some 20,000 working mills.

关于不同类型水车的相对效率有很多争论。

There was much debate on the relative efficiencies of different types of waterwheels.

从1650年到1800年这段时间，人们对不同设计进行了一些出色的、科学的和技术性的调查。

The period from about 1650 until 1800 saw some excellent scientific and technical investigations of different designs.

他们透露，输出功率从1马力到最大轮子产生的60马力不等，并确认，为了达到最高效率，水应该尽可能平稳地流过叶片，以最小的速度流走，几乎丧失了所有的动能。

They revealed output powers ranging from about 1 horsepower to perhaps 60 for the largest wheels and confirmed that for maximum efficiency, the water should pass across the blades as smoothly as possible and fall away with minimum speed, having given up almost all of its kinetic energy.

（他们还证明了，从原理上讲，在效率竞赛中获胜的应该是打捞筒轮。打捞筒轮是一种用头顶上的水流来驱动轮的轮子。）

(They also proved that, in principle, the overshot wheel, a type of wheel in which an overhead stream of water powers the wheel, should win the efficiency competition.)

但随后蒸汽动力进入了人们的视野，让人们对水力发电的整个未来产生了怀疑。

But then steam power entered the scene, putting the whole future of waterpower in doubt.

一位能源分析家在1800年的文章中对水力发电的未来描绘了一幅非常悲观的画面。

An energy analyst writing in the year 1800 would have painted a very pessimistic picture of the future for waterpower.

烧煤的蒸汽机开始取代（水车），并且水车很快就过时了。

The coal-fired steam engine was taking over, and the waterwheel was fast becoming obsolete.

然而，就像许多后来的专家一样，这个人也遭受了无法预见未来的痛苦。

However, like many later experts, this one would have suffered from an inability to see into the future.

一个世纪后，情况完全不同了：那时，世界上已经有了电力工业，四分之一的发电能力是由水力提供的。

A century later the picture was completely different: by then, the world had an electric industry, and a quarter of its generating capacity was water powered.

电力工业的发展是19世纪一系列重大科学发现和电技术发展的结果，但我们现在所说的水电技术的重大变化也起了作用。

The growth of the electric-power industry was the result of a remarkable series of scientific discoveries and developments in electrotechnology during the nineteenth century, but significant changes in what we might now call hydro (water) technology also played their part.

1832年，也就是迈克尔·法拉第发现磁场变化会产生电场的那一年，一位年轻的法国工程师为一种新的、效率更高的水车申请了专利。

In 1832, the year of Michael Faraday’s discovery that a changing magnetic field produces an electric field, a young French engineer patented a new and more efficient waterwheel.

他的名字叫 Benoit Fourneyron，他的装置是第一个成功的水轮机。

His name was Benoît Fourneyron, and his device was the first successful water turbine.

（涡轮这个词来自拉丁涡轮：旋转的东西）。

(The word turbine comes from the Latin turbo: something that spins).

将近2000年没有改变的水车终于被取代了。

The waterwheel, unaltered for nearly 2,000 years, had finally been superseded.

法拉第在电力方面的发现被转化成全面的发电站花了半个世纪来发展。

Half a century of development was needed before Faraday’s discoveries in electricity were translated into full-scale power stations.

1881年，英国萨里郡魏河岸边的戈达明电站创造了世界上第一个公共电力供应系统。

In 1881 the Godalming power station in Surrey, England, on the banks of the Wey River, created the world’s first public electricity supply.

这种最现代的技术的动力来源是传统的水车。

The power source of this most modern technology was a traditional waterwheel.

不幸的是，这个早期的工厂遇到了许多可再生能源都遇到的问题：韦河的水流不稳定，水车很快就被蒸汽机取代了。

Unfortunately this early plant experienced the problem common to many forms of renewable energy: the flow in the Wey River was unreliable, and the waterwheel was soon replaced by a steam engine.

从这个原始的开始，电力工业在19世纪的最后20年里以几乎没有任何技术能超越的速度发展。

From this primitive start, the electric industry grew during the final 20 years of the nineteenth century at a rate seldom if ever exceeded by any technology.

在不到十年的时间里，单个发电站（其中许多是水力发电站）的发电能力从几千瓦上升到超过一兆瓦。

The capacity of individual power stations, many of them hydro plants, rose from a few kilowatts to over a megawatt in less than a decade.

The word “harnessed” in the passage is closest in meaning to

In paragraph 1, uncertainty is expressed about all of the following aspects of the early development of waterpower EXCEPT

According to paragraph 2, what was true of the waterpower mills built throughout the Roman Empire?

The phrase “the applications of waterpower” in the passage is closest in meaning to

According to paragraph 4, which of the following was discovered as a result of scientific and technical investigations of waterpower conducted between 1650 and 1800?

The term “by then” in the passage refers to

According to paragraph 5, why did waterpower become more important by 1900?

According to paragraph 7, what problem did the early power station in the town of Godalming in Surrey, United Kingdom, face in providing electricity?

Look at the four squares  that indicate where the following sentence could be added to the passage. Happily, serious studies began to be conducted to help resolve disagreements.  Where would the sentence best fit? Click on a square  to add the sentence to the passage.

Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.

The History of Waterpower Moving water was one of the earliest energy sources to be harnessed to reduce the workload of people and animals. No one knows exactly when the waterwheel was invented, but irrigation systems existed at least 5,000 years ago, and it seems probable that the earliest waterpower device was the noria, a waterwheel that raised water for irrigation in attached jars. This device appears to have evolved no later than the fifth century B.C., perhaps independently in different regions of the Middle and Far East. The earliest waterpower mills were probably vertical-axis mills for grinding corn, known as Norse or Greek mills, which seem to have appeared during the first or second century B.C. in the Middle East and a few centuries later in Scandinavia. In the following centuries, increasingly sophisticated waterpower mills were built throughout the Roman Empire and beyond its boundaries in the Middle East and northern Europe. In England, the Saxons are thought to have used both horizontal- and vertical-axis wheels. The first documented English mill was in the eighth century, but three centuries later about 5,000 were recorded, suggesting that every settlement of any size had its mill. Raising water and grinding corn were by no means the only uses of the waterpower mill, and during the following centuries, the applications of waterpower kept pace with the developing technologies of mining, iron working, paper making, and the wool and cotton industries. Water was the main source of mechanical power, and by the end of the seventeenth century, England alone is thought to have had some 20,000 working mills. There was much debate on the relative efficiencies of different types of waterwheels.  The period from about 1650 until 1800 saw some excellent scientific and technical investigations of different designs.  They revealed output powers ranging from about 1 horsepower to perhaps 60 for the largest wheels and confirmed that for maximum efficiency, the water should pass across the blades as smoothly as possible and fall away with minimum speed, having given up almost all of its kinetic energy.  (They also proved that, in principle, the overshot wheel, a type of wheel in which an overhead stream of water powers the wheel, should win the efficiency competition.)  But then steam power entered the scene, putting the whole future of waterpower in doubt. An energy analyst writing in the year 1800 would have painted a very pessimistic picture of the future for waterpower. The coal-fired steam engine was taking over, and the waterwheel was fast becoming obsolete. However, like many later experts, this one would have suffered from an inability to see into the future. A century later the picture was completely different: by then, the world had an electric industry, and a quarter of its generating capacity was water powered. The growth of the electric-power industry was the result of a remarkable series of scientific discoveries and developments in electrotechnology during the nineteenth century, but significant changes in what we might now call hydro (water) technology also played their part. In 1832, the year of Michael Faraday’s discovery that a changing magnetic field produces an electric field, a young French engineer patented a new and more efficient waterwheel. His name was Benoît Fourneyron, and his device was the first successful water turbine. (The word turbine comes from the Latin turbo: something that spins). The waterwheel, unaltered for nearly 2,000 years, had finally been superseded. Half a century of development was needed before Faraday’s discoveries in electricity were translated into full-scale power stations. In 1881 the Godalming power station in Surrey, England, on the banks of the Wey River, created the world’s first public electricity supply. The power source of this most modern technology was a traditional waterwheel. Unfortunately this early plant experienced the problem common to many forms of renewable energy: the flow in the Wey River was unreliable, and the waterwheel was soon replaced by a steam engine. From this primitive start, the electric industry grew during the final 20 years of the nineteenth century at a rate seldom if ever exceeded by any technology. The capacity of individual power stations, many of them hydro plants, rose from a few kilowatts to over a megawatt in less than a decade.