TPO 6 阅读 Powering the Industrial Revolution问题

xujieflankUID: 2924357

大清早错了好多好桑心，感觉思路有问题在此求教：上文上题：
The source had long been known but not exploited. Early in the eighteenth century, a pump had come into use in which expanding steam raised a piston in a cylinder, and atmospheric pressure brought it down again when the steam condensed inside the cylinder to form a vacuum. This “atmospheric engine,” invented by Thomas Savery and vastly improved by his partner, Thomas Newcomen, embodied revolutionary principles, but it was so slow and wasteful of fuel that it could not be employed outside the coal mines for which it had been designed. In the 1760s, James Watt perfected a separate condenser for the steam, so that the cylinder did not have to be cooled at every stroke; then he devised a way to make the piston turn a wheel and thus convert reciprocating (back and forth) motion into rotary motion. He thereby transformed an inefficient pump of limited use into a steam engine of a thousand uses. The final step came when steam was introduced into the cylinder to drive the piston backward as well as forward, thereby increasing the speed of the engine and cutting its fuel consumption.

5. According to paragraph 2, the “atmospheric engine” was slow because
○it had been designed to be used in coal mines
○the cylinder had to cool between each stroke
○it made use of expanding steam to raise the piston in its cylinder
○it could be operated only when a large supply of fuel was available

卤煮选了C，排除法做的。
阅读过程及思路是酱紫： 首先，TS发明了机器，TM做了改进，但是慢（题干定位），接下来瓦特继续改进，以seperate condenser 使得机器不用每次都技术冷却了（这里没有提到冷却可以提速啊，所以被卤煮无视继续念了下去），又改了第二轮，最后第三轮改动，把piston改成可以来回抽送了，这回increase spped of engine了，然后看题，AD首先排除，看到B在文章没有提及增速，所以排除选了C。。觉得从某种程度上也是对机器内的piston改进，心里觉得很踏实，然后错了。。。）
请告诉我，我不是唯一。
我感觉错在自己输在思维上了，求正！

fifalalalaUID: 3416635

……卤煮……这题……是基于我的物理知识……选的……
思维上……帮不上你忙。。。
【所有蒸汽机都是你选的那个选项作工作原理的

xujieflankUID: 2924357

额。。好吧~谢谢楼上

噢GOGOUID: 3481439

but it was so slow and wasteful of fuel that it could not be employed outside the coal mines for which it had been designed. In the 1760s, James Watt perfected a separate condenser for the steam, so that the cylinder did not have to be cooled at every stroke

前面说slow and wasteful 后面说Watt perfect 了它 可以让cylinder不需要每个stroke都cool。 所以原来慢的原因应该是原来的 每个stroke都要cool

xujieflankUID: 2924357

噢GOGO 发表于 2014-4-17 17:17
but it was so slow and wasteful of fuel that it could not be employed outside the coal mines for whi ...

瞬间想明白了，谢谢啦:victory: