金属切削加工中的切削用量要素有（）个。
A、2
B、3
C、4
D、5
参考答案：B
如果79°-2x与21°+6x互补，那么x=______度．
If what parents say is not ______ with what they do, it will have a bad effect on their children.
A．contrary
B．consistent
C．confident
D．considerate
