(来学网)管电压在80~150kV时,特征X线所占比例约是
  • A.
    (来学网)1%~5%
  • B.
    (来学网)5%~10%
  • C.
    (来学网)10%~28%
  • D.
    (来学网)28%~50%
  • E.
    (来学网)50%~72%