(来学网)桩冠修复时理想的冠桩直径为根径的
  • A.
    (来学网)1/3
  • B.
    (来学网)1/2
  • C.
    (来学网)2/3
  • D.
    (来学网)1/4
  • E.
    (来学网)2/5