(来学网)X线胶片的感光银盐颗粒大小平均为
  • A.
    (来学网)1.71nm
  • B.
    (来学网)1.71μm
  • C.
    (来学网)1.71mm
  • D.
    (来学网)1.71cm
  • E.
    (来学网)1.71dm