A.fAuB.fCuC.fAu+fCuD.f平均=1/4fAu+3/4fCu
A.1/4和3/4B.3/4和1/4C.1/4和1/4D.3/4和3/4
A.规则斑点B.同心圆环C.大晕斑D.不连续弧段的同心圆环,弧段对称分布