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根据短文内容理解，选择正确答案。A
Many people think the camel stores water in its hump (驼峰), but it does not. Instead, the camel stores something else there—food. The camel's hump is really a hump of fat (脂肪). The camel is often called "a ship of the desert". When the camel is not travelling and is in a place where there is much food and water, it eats and drinks a lot. As it does so, its hump rises from the fat its body makes. Then, when the camel is travelling through the desert and when there is no food, it can live off the stored fat.
A camel can go on for days or weeks with little food or water. However, when its hunger reaches the starvation (饿死)point, its hump shrinks (收缩) and may even slip off its back and hang down its side.
Camels are not fussy (挑剔的) about what they eat. Thorny (多刺的) plants don't hurt their mouths, grass of any kind will do and so will hay, dry grain and cactuses (干草, 干粮, 仙人掌).
There are one hump camels and two hump camels. Camels with one hump are called Arabian camels. They come from North Africa. Camels with two humps are from Asia.
