A.82 B.78 C.80 D.76
A.直徑 B.寬度 C.模數(shù) D.齒數(shù)
A.a-b-c-e-f-d-g B.a-b-d-e-c-f-g C.b-a-e-c-f-d-g D.b-a-e-f-c-d-g