下面哪个不是下颌骨薄弱部位 ["A．正中联合","B．颏孔区","C．喙状突颈部","D．髁状突颈部","E．下颌角"]
下牙槽神经人 ["A．下颌孔 ","B．颏孔 ","C．卵圆孔 ","D．圆孔 ","E．眶下孔"]
不同铝合金可通过哪些途径达到强化目的？
口腔的后界为 ["A．腭垂","B．舌腭弓","C．咽腭弓","D．咽门","E．舌根"]
呈小管结构，内含造牙本质细胞芽突的为 ["A．牙釉质","B．牙本质","C．牙骨质","D．牙髓","E．牙周膜"]
韧皮部卸出的途径有两条：一条是（）途径，另一条是（）途径。
