A human hair consists mainly of a protein called Keratin. It also contains some moisture and the trace metals and minerals found in the rest of the body. 人类的头发主要由一种叫角朊的蛋白质组成，并含有水分及在身体其他部分也可找到的微量金属和矿物质。
The only living part of hair is underneath the scalp--when the hair had grown through the scalp it is dead tissue. 头发唯一有生命的部分是在头皮下面，当它长出头皮时便成为无生命组织。
