儿科护理学范围应除外A．健康、亚健康和患病儿童的护理 B．儿童保健 C．疾病预防 D

已知下面三个数据:7.2×10^-4、4.6×10^-4、4.9×10^-10分别是下列有关的三种酸的电离常数,若已知下列反应可以发生:NaCN+HNO₂HCN+NaNO₂,NaCN+HFHCN+NaF,NaNO₂+HFHNO₂+NaF

由此可判断下列叙述不正确的是(　　)

A．K(HF)=7.2×10^-4

B．K(HNO₂)=4.9×10^-10

C．根据其中两个反应即可得出结论

D．K(HCN)<K(HNO₂)<K(HF)

BTS机房内接地电阻应该小于（）欧姆。

A.1

B.5

C.10

D.25

They _______ on the program for almost one week before I joined them, and now we ________ it as no good results have come out so far.

A．had been working; are still working

B．had worked; were still working

C．have been working; have worked

D．have worked; are still working

挣值分析法

适宜用甲苯法测定水分的药材为

A．大黄
B．牛膝
C．商陆
D．当归
E．黄芩