托福阅读练习：WIMMING MACHINES(翻译).docx

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托福阅读练****SWIMMING MACHINES(翻译)
摘要: 托福阅读考试中会碰到一些练****例如本文为大家介绍的托福阅读练****SWIMMING MACHINES(翻译)。小编为大家搜集整理了托福阅读练****SWIMMING MACHINES(翻译),希望给大家的考试带来帮助。下面我们一起来看看吧!

托福阅读练****SWIMMING MACHINES(英文)

Tunas, mackerels, and billfishes (marlins, sailfishes, and swordfish) swim continuously. Feeding, courtship, reproduction, and even "rest" are carried out while in constant motion. As a result, practically every aspect of the body form and function of these swimming "machines" is adapted to enhance their ability to swim.

Many of the adaptations of these fishes serve to reduce water resistance (drag). Interestingly enough, several of these hydrodynamic adaptations resemble features designed to improve the aerodynamics of high-speed aircraft. Though human engineers are new to the game, tunas and their relatives evolved their "high-tech" designs long ago.

Tunas, mackerels, and billfishes have made streamlining into an art form. Their bodies are sleek pact. The body shapes of tunas, in fact, are nearly ideal from an engineering point of view. Most species lack scales over most of the body, making it smooth and slippery. The eyes lie flush with the body and do not protrude at all. They are also covered with a slick, transparent lid that reduces drag. The fins are stiff, smooth, and narrow, qualities that also help cut drag. When not in use, the fins are tucked into speci