题干

牛通过吃草从草中获得化合物和元素,那么,牛和草体内的各种化学元素(  )

A:种类差异很大,含量大体相同

B:种类和含量差异都很大

C:种类和含量都是大体相同的

D:种类大体相同,含量差异很大

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D

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