数控机床指令代码主要有哪些
参考答案：准备功能G指令、进给功能F指令、主轴速度S指令、刀具功能T指令、辅助功能M指令。
My parents have promised to come to see me before I _______ for Africa.
A．have left
B．leave
C．left
D．will leave
He found it no pleasure ____ himself of the habit of playing computer games day and night.
A．ridding
B．getting rid
C．changing
D．defending
