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

游客2024-02-27  13

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【S1】______powerful enough to shoot astronauts【S2】______  the earth’s gravitational pull and land them on the moon. We have now become travelers space.
    Impressive and complex as it may appear, the rocket, which was【S3】______in China over 800 years ago, is a relatively simple device. Fuel that is【S4】______in the rocket engine changes into gas. The hot and rapidly【S5】______gas must escape, but it can do so only through an opening that【S6】______backward. As the gas is【S7】______with great force, it【S8】______the rocket in the opposite direction. Like the kick of a gun when it is fired, it【S9】______the laws of nature【S10】______by Sir Isaac Newton when he discovered that" for every action, there is an equal and opposite reaction."

A—follows            B—developed            C—faces              D—proved
E—radiated           F—expanding            G—pushes             H—described
I—turns              J—burned               K—beyond             L—invented
M—despite            N—round                O—dispersed [br] 【S5】

选项

答案 F

解析 根据句子意思判断,应选expanding gas膨胀的气体。
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