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 nearly white. One form even has vivid purple tentacles. Usually the crea- tures are cucumber-shaped--hence their name and because they are typically rock inhabitants, this shape, combined with their 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 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 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 the water becomes too polluted. According to the passage, why is the shape of sea cucumber important
A. Because it helps them digest food.
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
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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 nearly white. One form even has vivid purple tentacles. Usually the crea- tures are cucumber-shaped--hence their name and because they are typically rock inhabitants, this shape, combined with their 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 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 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 the water becomes too polluted. The fourth paragraph of the passage primarily discusses______.
A. the reproduction of sea cucumbers
B. the food sources of sea cucumbers
C. the eating habits of sea cucumbers
D. threats to sea cucumbers’ existence
Even today, through the hustle and bustle of Nevsky Prospect, St Petersburg’smain street, the classical beauty of the city mesmerizes the eye.A.throughB.hustle and bustleC.classicalD.mesmerizes
患者男性,37岁,农民。用乐果喷洒果树,出现恶心、呕吐、出汗。查体可见神志清楚,心肺未闻异常。 以下哪些说法是正确的()
A. 误服毒药后6h洗胃有效,超过6h不用洗胃
B. 吞服强酸时,可用弱碱中和
C. 氰化物中毒采用亚硝酸盐-硫代硫酸钠
D. 阿片类麻醉药的解毒药是纳洛酮
E. 氟马西尼是苯二氮卓类药物的解毒药
In deciding to undertake dangerous pursuits, people usually strive for their maximum personal ability rating, when they are challenged but can be victorious, rather thanmerely surmounting the mediocre.A.usuallyB.whenC.challengedD.surmounting the mediocre