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。
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。
The body's endocrine system may interpret this loss of calcium as serious enough to warrant leaching the mineral from bone.
人体的内分泌系统会判断这些钙的流失是否严重到引起骨骼中的矿物质也流失。
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
应用推荐