单项选择题
A.6W6MoCr4VB.3Cr2W8VC.0Cr16Ni4Cu3Nb(PCR)D.10Ni3MnCuAl(PMS)
A.知觉模式B.显著性模式C.优先顺序模式D.融合模式
A.During three weeksB.since three weeksC.three weeks agoD.for three weeks