单项选择题
A.5微克/(厘米2·星期) B.0.5微克/(厘米2·星期) C.0.05微克/(厘米2·星期) D.50微克/(厘米2·星期)
A.GB/T 21198.6B.GB/T 17832C.GB/T 15072.1D.GB/T 25934.1
A.GB/T21198.1 B.GB/T21198.6 C.GB/T19720 D.GB/T9288