(来学网)诊断用X线机房的主防护应有铅当量厚度是
  • A.
    (来学网)0.5mm
  • B.
    (来学网)lmm
  • C.
    (来学网)2mm
  • D.
    (来学网)3mm
  • E.
    (来学网)5mm