Fluoride is a trace element which human body need, but it can arouse injure on bone System if one who have taken in too much.

氟是人体必需的微量元素，但摄入过量能引起骨相系统损害。

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He believes that as far back as 30,000 B.C., hunters may have used a system of notation, engraved on bone and stone, to mark phases of the Moon.

他认为，远在公元前30,000年以前，猎人可能会用一套刻在骨头和石头上的符号系统来标记月相。

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Bone marrow cells are known to help restore blood and immune system function.

我们都知道，骨髓细胞可以造血，也可以恢复免疫系统的功能。

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One is because we understand the bone marrow system so much better than we understand all the other stem cell systems.

一个原因就是我们对骨髓系统的认识,远高于其他干细胞系统

耶鲁公开课 - 生物医学工程探索课程节选

Not only does the robot look Terminator-esque, but it's been designed to mimic the muscle system of a human (with bone-crushing strength, of course) and will be programmed with a semi-autonomous AI so that the android can learn new tasks, all of which is just a little too much like the Terminator for our comfort.

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According to the doctors, the bone marrow cells could re-educate the immune system so it wouldn't reject the hands.

CNN: Pastry chef receives double hand transplant

Hollis-Eden's drug, an immune system booster, appears to help the bone marrow fend off toxic effects of radiation and could be used by troops going into battle to protect against the effects of dirty bombs.

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