对牙齿有支持、营养、感觉作用的为
A．牙冠B．牙根C．牙颈D．牙周膜E．牙槽骨
参考答案：E
—Happy Halloween, Kitty.
—_____[ ]
A. Yes, I'm very happy.
B. Thanks. The same to you.
C. OK, you're right.
D. N0t at all.
安全制动必须有并联冗余的回油通道。
