2014年4月托福考试模拟试卷及答案(第四套)_第11页

　　Certainly no creature in the sea is odder than the common sea cucumber. All living

　　creature, especially human beings, have their peculiarities, but everything about the

　　little sea cucumber seems unusual. What else can be said about a bizarre animal that,

　　Line among other eccentricities, eats mud, feeds almost continuously day and night but can

　　(5) live without eating for long periods, and can be poisonous but is considered supremely

　　edible by gourmets?

　　For some fifty million years, despite all its eccentricities, the sea cucumber has

　　subsisted on its diet of mud. It is adaptable enough to live attached to rocks by its tube

　　feet, under rocks in shallow water, or on the surface of mud flats. Common in cool

　　(10) water on both Atlantic and Pacific shores, it has the ability to suck up mud or sand and

　　digest whatever nutrients are present.

　　Sea cucumbers come in a variety of colors, ranging from black to reddish-brown to

　　sand-color and nearly white. One form even has vivid purple tentacles. Usually the

　　creatures are cucumber-shaped-hence their name-and because they are typically

　　(15) rock inhabitants, this shape, combined with flexibility, enables them to squeeze

　　into crevices where they are safe from predators and ocean currents.

　　Although they have voracious appetites, eating day and night, sea cucumbers have

　　the capacity to become quiescent and live at a low metabolic rate-feeding sparingly

　　or not at all for long periods, so that the marine organisms that provide their food have

　　(20) a chance to multiply. If it were not for this faculty, they would devour all the food

　　available in a short time and would probably starve themselves out of existence.

　　But the most spectacular thing about the sea cucumber is the way it defends itself.

　　Its major enemies are fish and crabs, when attacked, it squirts all its internal organs

　　into the water. It also casts off attached structures such as tentacles. The sea cucumber

　　(25) will eviscerate and regenerate itself if it is attacked or even touched; it will do the same

　　if the surrounding water temperature is too high or if the water becomes too polluted.

　　Compared with other sea creatures the sea cucumber is very

　　(A) dangerous

　　(B) intelligent

　　(C) strange

　　(D) fat