校正PNa表时，采用PNa4定位液定位，其［Na+］为（）mg／L
A.23
B.0.023
C.0.23
D.2.3
参考答案：D
It will be another 50 years ______ our country is expected to reach the level of a medium developed country.
A．since
B．before
C．that
D．when
中国药品通用名称缩写为（）
A.CAND
B.CDNA
C.CAD
D.CDAN
E.CADN
