(来学网)放疗摆位中铅挡块厚度(全防护)为
  • A.
    (来学网)1个HVL
  • B.
    (来学网)2个HVL
  • C.
    (来学网)4个HVL
  • D.
    (来学网)5个HVL
  • E.
    (来学网)6个半HVL