Directions: Complete the table below by indicating which features of fishes are associated in the passage with reducing water resistance and which are associated with increasing thrust. This question is worth 3 points.
Features of Fishes
1. The absence of scales from most of the body
2. The ability to take advantage of eddies
3. The ability to feed and reproduce while swimming
4. Eyes that do not protrude
5. Fins that are stiff, narrow, and smooth
6. The habit of swimming with the mouth open
7. A high, narrow tail with swept-back tips
有的托福阅读文章是全文的对照对比，有的则是重点段落的对照对比。这种题目需要先识别要求对比的内容，并且从原文中搜寻对应的文章段落。本题要求对比REDUCING WATER RESISTANCE和INCREASING THRUST，因此我们先通过读每段的关键句来确定对比内容所在段落。
第三自然段：Tunas, mackerels, and billfishes have made streamlining into an art form. Their bodies are sleek and compact. 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 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.
第八自然段：There are adaptations that increase the amount of forward thrust as well as those that reduce drag. Again, these fishes are the envy of engineers. Their high, narrow tails with swept-back tips are almost perfectly adapted to provide propulsion with the least possible effort. Perhaps most important of all to these and other fast swimmers is their ability to sense and make use of swirls and eddies (circular currents) in the water. They can glide past eddies that would slow them down and then gain extra thrust by "pushing off" the eddies. Scientists and engineers are beginning to study this ability of fishes in the hope of designing more efficient propulsion systems for ships.