[单项选择]
3
Certainly no creature in the sea is odder than the common sea cucumber. All living creatures, 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" among other eccentricities, eats mud, feeds almost continuously day and night but can live with- out 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 sub- sisted 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 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-colored and near
A. Because it helps them digest food.
B. Because it helps them protect themselves from danger.
C. Because it makes it easier for them to move through mud.
D. Because it makes them attractive to fis