Paragraph 1：In Britain one of the most dramatic changes of theIndustrial Revolution was the harnessingof power.Until the reign of George Ⅲ(1760-1820)，available sources of power forwork and travel had not increased since the Middle Ages.There were threesources of power：animal or human muscles;the wind, operating on sail orwindmill; and running water.Only the lastof these was suited at all to the continuous operating of machines, andalthough waterpower abounded in Lancashire and Scotland and ran grain mills aswell as textile mills, it had one great disadvantage:streams flowedwhere nature intended them to and water-driven factories had to be located ontheir banks whether or not the location was desirable for other reasons.Furthermore, even the mostreliable waterpower varied with the seasons and disappearedin a drought, the new age of machinery, in short, could not have been born without a new source of bothmovable and constant power.
Paragraph 2: The source had longbeen known but not exploited.Early inthe century, a pump had come into use inwhich expanding steam raised a piston in a cylinder,andatmospheric pressure brought it down again when the steam condensed inside thecylinder to form a vacuum.This “atmosphericengine,” invented by Thomas Savery and vastly improved by hispartner.Thomas Newcomen, embodiedrevolutionary principles, but it was so slow and wasteful of fuel that it couldnot be employed outside the coal mines for which it had been designed.In the1760s, James Watt perfected a separate condenser for the steam, so that the cylinder did not have to be cooled at everystroke; then he devised a way to make thepiston turn a wheel and thus convert reciprocating (back and forth) motion intorotary motion.He thereby transformed an inefficient pump of limited use into asteam engine of a thousand uses.The final step came when steam was introduced intothe cylinder to drive the piston backward as well as forward thereby increasingthe speed of the engine and cutting its fuel consumption.
1.Which of the sentences belowbest expresses the essential information in the highlighted sentence in thepassage? Incorrect choices change the meaning in important ways or leave outessential information.
○ Running water was the best power source for factoriessince it could keep machines operating continuously but since it was abundantonly in Lancashire and Scotland, most mills andfactories that were located elsewhere could not be water driven.
○ The disadvantage ofusing waterpower is that streams do not necessarily flow in places that are the most suitable forfactories which explains why so many water—powered grain and textile mills werelocated in undesirable places
○ Since machines couldbe operated continuously only where running water was abundant, grain andtextile mills as well as other factories tended to be located only inLancashire and Scotland.
○ Running water was theonly source of power that was suitable for the continuous operation of machines, but to make use of it factories had to be located wherethe water was, regardless of whether such locations made sense otherwise.
