烟点
参考答案：
指在不通风的情况下加热油脂观察到油脂发烟时的温度。一般在240℃左右。
X线片上显示为包绕牙根的，连续不断的低密度线条状影像（）
A.牙釉质
B.牙骨质
C.牙槽骨
D.牙周膜
E.骨硬板
It is only when a football player has aged and been through many battles ________ he learns an important lesson: there is no “I” in “team”.
A．after
B．before
C．what
D．that
