官方真题Official6托福阅读词汇真题练习——exploited&vastly

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Paragraph 2: 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. 【官方真题Official6-Powering the Industrial Revolution】

3. The word “exploited” in the passage is closest in meaning to

○utilized

○recognized

○examined

○fully understood

4. The word “vastly” in the passage is closet in meaning to

○quickly

○ultimately

○greatly

○initially

答案：(1)(3)