I've heard him _______ about you often. [ ]
A. spoke
B. speaks
C. speak
答案:C
严重贫血,Hb<60g/L时为什么不会出现发绀
A.皮肤、黏膜难以观察
B.血氧饱和度高于66%
C.还原血红蛋白量不到50G/L(5G/D
D.贫血氧合血红蛋白高
E.动脉血氧分压高
皮亚杰认为适应有三种方式,即同化、顺应和______。