题目内容

一群在实验室里研究老鼠体内的钙的新陈代谢的科学家发现，去除老鼠的甲状旁腺可以导致老鼠血液中的钙的水平比正常水平低得多。这个发现使科学家们假设甲状旁腺的功能是调节血液中的钙的水平。当钙的水平降到正常范围之下，它就会升高钙的水平。在进一步的试验中，科学家们不但去除了老鼠的甲状旁腺，而且去除了它们的肾上腺，他们出乎意料地发现老鼠血液中钙的水平的下降比单是去除甲状旁腺时慢得多。下面哪一项如果正确，能与科学家们的假设相一致地解释那个出入意料的发现( )

A. 肾上腺的作用是降低血液中钙的水平。
B. 肾上腺与甲状旁腺在调节血液中钙的水平时作用是一样的。
C. 甲状旁腺的缺乏能促使肾上腺增加血液中的钙的水平。
D. 如果只是把老鼠的肾上腺去除，而没有把其他的腺移去，这只老鼠的血液中的钙的水平将会维持不变。

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