切削热主要是由于工件与刀具后刀具面之间的摩擦产生的。
参考答案:错
I want to _______ a _______ basketball player, but my mother don't agree with me.[ ]
A. be, profession
B. be, professional
C. do, professional
D. do, profession
GPS在测量定位时,接收卫星信号的同时也发射信号。