阳极电泳槽液的pH值范围应在（）。
A.7—8
B.l1—12
C.5—6
D.8一10
参考答案：D
I have seldom seen my mother ________ pleased with my progress as she is now. [ ]
A. so
B. very
C. too
D. rather
当垫层厚度大于( )时，横向缩缝应做假缝。
A．60mmB．100mmC．120mmD．150mm
