下列（）加工不存在加工原理误差。
A.数控铣削曲面
B.车削模数蜗杆
C.滚切齿轮
D.拉削键槽
参考答案：D
"For your coming vacation, why _________ corning to Guiyang?" "Good idea!"
A. not consider B. don't consider C. to consider
髓弓
