慢性特发性血小板减少性紫癜合并贫血最适宜的检查是()
A.血清铁蛋白测定
B.血清叶酸测定
C.血红蛋白电泳
D.酸溶血试验
E.红细胞渗透性脆性试验
参考答案:A
一段导体两端电压为2V,导体中电流为0.5A,此导体的电阻是______Ω.如果该导体两端电压增大到4V,导体中的电流是______A.如果两端的电压降到0V,导体的电阻是______Ω.
He knew nothing about the matter, but he talked as if he __it.
A.knows
B.knew
C.had known
D.would know