---What’s the matter with your boyfriend?

---I can’t stand _____when he often ignores me and talks with other girls.

A．one

B．that

C．him

D．it

下述上颌尖牙牙冠唇面形态描述不正确的是（）

A.尖牙唇面轮廓呈五边形

B.两条牙尖嵴相交成直角

C.牙尖顶偏近中方向

D.唇面外形高点在颈1／3处

E.唇轴嵴较显著