增强桩冠固位的方法,不妥当的是
A.尽可能保留残冠的健康牙体组织
B.尽可能利用根管长度
C.增加桩与管壁的密合度
D.根管预备成柱形
E.选用适当的粘结剂
参考答案:D
My sister is only four years old, but she can look after ________ now.
A.she
B.her
C.hers
D.herself