(来学网)电能通过X线管转变为X能的比例很小,一般小于
  • A.
    (来学网)1%
  • B.
    (来学网)0.5%
  • C.
    (来学网)0.4%
  • D.
    (来学网)0.2%
  • E.
    (来学网)0.1%
正确答案:
A