Paragraph 3: The source had long been known but not exploited.
Early in the 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.
想請問一下各位
從哪邊可以看出 選項的different way 再文章的哪裡
以及 used steam to move a piston in a cylinder
WATT和之前的人不是都有用嗎 為什麼有差別呢??
感謝各位
6. According to paragraph 2, Watt's steam engine differed from
earlier steam engines, in each of the following ways, except:
○ It used steam to move a piston in a cylinder.
○ It worked with greater speed.
○ It was more efficient in its use of fuel.
○ It could be used in many different ways.
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