(来学网)当毛细血管内还原血红蛋白超过多少时出现发绀
  • A.
    (来学网)30g/L
  • B.
    (来学网)40g/L
  • C.
    (来学网)50g/L
  • D.
    (来学网)60g/L
  • E.
    (来学网)100g/L