A.下降 B.上升 C.不变 D.显著上升
A.Y B.YJ C.PVC D.V
A.1.3 B.1.0 C.0.92
A.K1>K2 B.K2>K1 C.K1＝K2 D.K1≠K2
A.1.2mm B.1.4mm C.1.6mm D.1.8mm
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