(来学网)支托长度应为前磨牙颌面近远中径的
  • A.
    (来学网)1/4
  • B.
    (来学网)1/3
  • C.
    (来学网)1/2
  • D.
    (来学网)2/3
  • E.
    (来学网)3/4