血中Hb含量低于多少时,即使重度缺氧,也难以出现发绀A.<50g/L B.<60g/ 发布时间:2017-05-26 02:20 │ 来源:www.tikuol.com 题型:单项选择题 问题: 血中Hb含量低于多少时,即使重度缺氧,也难以出现发绀A.<50g/LB.<60g/LC.<70g/LD.<80g/LE.<90g/L