消除进给丝杠轴向间隙的机构称（）
A.螺旋机构
B.进给机构
C.消隙机构
D.凸轮机构
参考答案：C
生产的90个零件中，有10个是废品，合格率是90%．______．
—Frank can’t find _____ dictionary. Can you lend _____ to_____?
—Certainly. [ ]
A. her; mine; her
B. /; yours; his
C. my; yours; he
D. his; yours; him
