Here ______________. [ ]
A. it is
B. is it
C. it does
答案:A
溃疡病合并瘢痕性幽门梗阻,频繁呕吐,最易出现
A.代谢性酸中毒B.代谢性碱中毒C.低镁血症D.低钙血症E.高渗性脱水
制作简易防毒口罩应注意哪几点?