She used a slither of tooth enamel the size of a nail clipping to trace his origins.
埃文斯通过大小相当于小钉的牙齿瓷釉（珐琅）质，来确定他的来历。
2
Conclusion in tooth shape keys, the tooth slope angel increases, along with slope Angle of duplicated trace decrease.
结论凸齿钥匙上仿形刀增配痕迹倾斜角度随齿坡角的增大而减小。
3
There are some characteristics about it, for example, highly tracking accuracy and tracking function etc. These characteristics need the require which can accurately measure toothtrace error.