用齿轮盘形铣刀铣削蜗杆，由于螺旋面铣削时的干涉现象，铣削后的蜗杆的齿形误差较大。
参考答案：对
．—Let’s back up. Where was I?
—______.
A．You were in the kitchen.
B．You left your book at home.
C．You were having a rest.
D．You were talking about the cause.
食用下列蛋类，需要配茶匙或咖啡匙的是（）。
A.煮蛋
B.煎蛋
C.炒蛋
D.水波蛋
