(来学网)血中Hb含量低于多少时,即使重度缺氧,亦难发现发绀
  • A.
    (来学网)<50g/L
  • B.
    (来学网)<60g/L
  • C.
    (来学网)<70g/L
  • D.
    (来学网)<80g/L
  • E.
    (来学网)<90g/L