钝化处理方法分为两类:重铬酸盐化学钝化和电化学钝化。现在的镀锡线主要采用阴极钝化,钝化膜的含铬量为3~9g/m2。
参考答案:错
润下为()
A.淡白舌
B.淡红舌
C.绛舌
D.红舌
E.紫舌
-Are there ___________ birds in the tree?
-Yes, there are __________.[ ]
A. any, any
B. some, some
C. any, some
D. some, any