单项选择题
A.1000-1200AB.1000-1300AC.1200-1400AD.900-1000A
A.银:115-150g/l、铜<38g/lB.银:145-150g/l、铜>38g/lC.银:145-150g/l、铜≤38g/lD.银:115-150g/l、铜≥38g/l
A.>10B.<10C.4-7D.5-7