单项选择题
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
A.铜粉;铁粉B.铁粉;铜粉C.铜粉;液碱D.铁粉;液碱