依据ISO15189，医学实验室必须设立的职位有（）
A.技术主管
B.质量主管
C.安全主管
D.财务主管
E.关键职位的代理人
参考答案：B, E
What do you have _____________ dinner _____________ Wednesdays? [ ]
A. at; for
B. on; at
C. for; on
_____ Shanghai you see today is quite _____ different city from what it used to be.
A. The, 不填 B. 不填, the C. The, a D. A. a
