余留牙的保留牙槽骨吸收的程度下列哪项是错误的（）
A.达到根2／3
B.达到根2/5
C.达到根1／3
D.达到根1/5
E.达到根1/2
参考答案：A
________, I think, and the problem could be settled.
A．So long as you keep up your spirits
B．A bit more effort
C．If you doubt your efforts
D．Making great efforts
何谓下压捆绑？
