下列哪些药物是透析患者常用的药物（）
A.磷结合剂
B.维生素D
C.铁剂
D.磺胺类
E.红细胞生成素
参考答案：A, B, C, E
下列转变过程属于氮的固定的是
A．氨气和HCl气体混合生成NH4Cl固体
B．氨的催化氧化
C．工业上用N2和H2 合成氨
D．NO遇到空气变为红棕色
In a nationwide poll, P people were asked 2 questions. If 2/5 answered "yes" to question 1, and of those 1/3 also answered "yes" to question 2, which of the following represents the number of people polled who did not answer "yes" to both questions ？（）
A. 2/15 P
B. 3/5 P
C. 3/4 P
D. 5/6 P
E. 13/15 P
