As far as classroom procedures are concerned, the teaching of listening generally follows three stages: pre-listening stage, while-listening stage, and post-listening stage.
【判断题】Milling machines may be manually operated, mechanically automated, or digitally automated via computer numerical control(CNC).这句话的意思是铣床可以通过手工操作,机械自动操作,或是计算机自动化数控操作。