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The Development of Steam Power
【1】By the eighteenth century, Britain wasexperiencing a severe shortage of energy. Because ofthe growth of population, most of the great forests of medieval Britain had long ago beenreplaced by fields of grain and hay. Wood was in ever-shorter supply, yet it remainedtremendously important. It served as the primary source of heat for all homes and industriesand as a basic raw material. Processed wood (charcoal) was the fuel that was mixed with ironore in the blast furnace to produce pig iron (raw iron). The iron industry’s appetite for woodwas enormous, and by 1740 the British iron industry was stagnating. Vast forests enabledRussia to become the world’s leading producer of iron, much of which was exported to Britain. But Russia’s potential for growth was limited too, and in a few decades Russia would reach thebarrier of inadequate energy that was already holding England back.
【2】As this early energy crisis grew worse, Britain looked toward its abundant and widelyscattered reserves of coal as an alternative to its vanishing wood. Coal was first used in Britainin the late Middle Ages as a source of heat. By 1640 most homes in London were heated withit, and it also provided heat for making beer, glass, soap, and other products. Coal was notused, however, to produce mechanical energy or to power machinery. It was there thatcoal’s potential wad enormous.
【3】As more coal was produced, mines were dug deeper and deeper and were constantlyfilling with water. Mechanical pumps, usually powered by hundreds of horses waling in circles atthe surface, had to be installed Such power was expensive and bothersome. In an attempt toovercome these disadvantages, Thomas Savery in 1698 and Thomas Newcomen in 1705 invented the first primitive steam engines. Both engines were extremely inefficient. Bothburned coal to produce steam, which was then used to operate a pump. However, by theearly 1770s, many of the Savery engines and hundreds of the Newcomen engines wereoperating successfully, though inefficiently, in English and Scottish mines.
【4】In the early 1760s, a gifted young Scot named James Watt was drawn to a critical studyof the steam engine. Watt was employed at the time by the University of Glasgow as a skilledcrafts worker making scientific instruments. In 1763: Watt was called on to repair a Newcomenengine being used in a physics course. After a series of observations, Watt saw that theNewcomen’s waste of energy could be reduced by adding a separate condenser. This splendidinvention, patented in 1769, greatly increased the efficiency of the steam engine. The steamengine of Watt and his followers was the technological advance that gave people, at least for awhile, unlimited power and allowed the invention and use of all kinds of power equipment.
【5】The steam engine was quickly put to use in several industries in Britain. It drained minesand made possible the production of ever more coal to feed steam engines elsewhere. Thesteam power plant began to replace waterpower in the cotton-spinning mills as well as otherindustries during the 1780s, contributing to a phenomenal rise in industrialization. TheBritish iron industry was radically transformed. The use of powerful, steam-driven bellows inblast furnaces helped iron makers switch over rapidly from limited charcoal to unlimited coke(which is made from coal) in the smelting of pig iron (the process of refining impure iron) after1770 in the 1780s, Henry Cort developed the puddling furnace, which allowed pig iron to berefined in turn with coke. Cort also developed heavy-duty, steam-powered rolling mills, whichwere capable of producing finished iron in every shape and form.
参考答案
1.B 2.BD 3.B 4.D 5.A 6.B 7.C 8.C 9.C 10.C 11.B 12.C 13.A 14.CDF
2017托福考试真题及范文：
真题回顾：
Students should choose the major such as science, technology, and engineering which can help them find good jobs instead of the major which they are interested in.
点睛：
题目大意：大学生应该选择哪种专业：能够帮助他们找到好工作的专业(比如科学类，技术类和工程类)VS自己喜欢的专业。此题目波波建议选择感兴趣的专业：理由如下1.学习更有动力 2.从长远来看，更有利于就业。
参考范文：
Under the current system of higher education, with the majors becoming increasingly diverse, how to choose an appropriate major has never failed to attract the attention of the general public. Most parents strongly recommend that it is much better to choose a major which can guarantee a good job, while college students, the receiver of higher education, tend to choose the field which caters to their interest. As far as I am concerned, the latter viewpoint is more reasonable, with the reasons listed below.
First of all, selecting the major that students like can help them to grasp the knowledge better. Just as a saying goes, interest is the best teacher, which is true of undergraduates. To illustrate, under the drive of interest, students are more likely to automatically devote more time and energy into what they major in, thus definitely having a better command of professional knowledge and skills imparted by teachers. By contrast, without any interest in what they are taught, college students who generally lack in self-motivation may do anything but study in class. For instance, on campus in China, it is not uncommon to see that many students squander their valuable time by taking a nap, whispering or even playing smart phones while attending the class. What's worse, some of them may even skip classes. The reason underlying the above phenomenon is nothing but lack of passion for what they learn.
Secondly, choosing a major students are interested in can do a better job in helping them secure a good job. As we all know, with the constant change and progress of society, the job market is also changing quickly. In other words, some promising industries a few years ago might very well become obsolete, which means that the major one chooses cannot necessarily guarantee a good job. By contrast, under such a society full of fierce competition, it is the professional skills and abilities people own that play the key role in landing a decent job. Obviously, only when people select the field they have passion for can they establish a solid foundation of specific knowledge and skills in this field. Therefore, the major catering to one's interest can better improve his or her competence, thus increasing their likelihood of securing a decent job.
Taking all the above into consideration, we can draw the conclusion that choosing the major which interests students is much better, in terms of making undergraduates have a better command of what they major in and find a suitable job.
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