The muscles of these fishes and the mechanism that maintains a warm body temperature are also highly efficient. A bluefin tuna in water of 7° C (45° F) can maintain a core temperature of over 25° C (77° F). This warm body temperature may help not only the muscles to work better, but also the brain and the eyes. The billfishes have gone one step further. They have evolved special "heaters" of modified muscle tissue that warm the eyes and brain, maintaining peak performance of these critical organs.
10. According to paragraph 9, which of the following is true of bluefin tunas?
○ Their eyes and brain are more efficient than those of any other fish.
○ Their body temperature can change greatly depending on the water temperature.
○ They can swim in waters that are much colder than their own bodies.
○ They have special muscle tissue that warms their eyes and brain.
做细节题的第一步就是“定位”，要找到原文答案所在的区间。题干中问到“bluefin tunas”，我们回到原文，找到定位句：…A bluefin tuna in water of 7° C (45° F) can maintain a core temperature of over 25° C (77° F)…，即蓝鳍金枪鱼可以在低于自己体温(25° C)的水温(7° C)中生活，所以正确答案选择第三个。而其它干扰选项在原文均有出现，但是并不属于题干所问内容。