2. 职称英语
  3. The rocket engine, with its steady roar like that of a waterfall or a thunde

The rocket engine, with its steady roar like that of a waterfall or a thunde

游客2025-01-31  11
问题     The rocket engine, with its steady roar like that of a waterfall or a thunderstorm, is an impressive symbol of the new space age. Rocket engines have proved powerful【C1】______to shoot astronauts【C2】______the earth’s gravitational【C3】______and put them on the moon. We have now【C4】______space travelers.
    Impressive and complex 【C5】______it may appear, the rocket, which was【C6】______in China over 800 years【C7】______, is a relatively simple device. Fuel that is【C8】______in the rocket engine changes【C9】______gas. The hot and rapidly expanding 【C10】______must escape, but it can do so only 【C11】______an opening that heads 【C12】______. As the gas is【C13】______with great force, it【C14】______the rocket in the【C15】______direction. Like the【C16】______of a gun when it is fired, it【C17】______the【C18】______ of nature described by Sir Isaac Newton when he found that "【C19】______every action, there is another equal and opposite【C20】______. " [br] 【C18】
选项 A、rules
B、regulations
C、mechanisms
D、laws
答案 D
解析
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