A.12% B.8% C.88% D.50% E.92%
A.唇面頸1/3與舌面頸1/3 B.唇面中1/3與舌面頸1/3 C.唇面切1/3與舌面頸1/3 D.唇面頸1/3與舌面中1/3 E.唇面切1/3與舌面中1/3