文勇的新托福黄金&ccedil

theperiodbefore1815andwhichdescribecharacteristicsoft

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Unformatted text preview: 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 special grooves or depressions so that they lie flush with the body and do not break up its smooth contours. Airplanes retract their landing gear while in flight for the same reason. 2. The word they in the passage refers to ○Qualities ○Fins ○Grooves ○Depressions 3. Why does the author mention that Airplanes retract their landing gear while in flight? ○To show that air resistance and water resistance work differently from each other ○To argue that some fishes are better designed than airplanes are ○To provide evidence that airplane engine have studied the design of fish bodies ○To demonstrate a similarity in design between certain fishes and airplanes Paragraph 4: Tunas, mackerels, and billfishes have even more sophisticated adaptations than these to improve their hydrodynamics. The long bill of marlins, sailfishes, and swordfish probably helps them slip through the water. Many supersonic aircraft have a similar needle at the nose. 4. The word sophisticated in the passage is closest in meaning to ○Complex ○Amazing ○Creative ○Practical 5. According to paragraph4, the long bills of marlins, sailfish, and swordfish probably help these fishes by 57 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 ○Increasing their ability to defend themselves ○Allowing them to change direction easily ○Increasing their ability to detect odors ○Reducing water resistance as they swim Paragraph 6: Because they are always swimming, tunas simply have to open their mouths and water is forced in and over their gills. Accordingly, they have lost most of the muscles that other fishes use to suck in water and push it past the gills. In fact, tunas must swim to breathe. They must also keep swimming to keep from sinking, since most have largely or completely lost the swim bladder, the gas­filled sac that helps most other fish remain buoyant. 6. According to the passage, which of the following is one of the reasons that tunas are in constant motion? ○They lack a swim bladder. ○They need to suck in more water than other fishes do. ○They have large muscles for breathing. ○They cannot open their mouths unless they are in motion. Paragraph 7: One potential problem is that opening the mouth to breathe detracts from the streamlining of these fishes and tends to slow them down. Some species of tuna have specialized grooves in their tongue. It is thought that these grooves help to channel water through the mouth and out the gill slits, thereby reducing water resistance. 7. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect answer choices change the meaning in important ways or leave out essential information, ○These fishes often have a problem opening their mouths while swimming. ○The streamlining of t...
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