上课
教师讲课；学生听课to teach a class; to attend a class
去上课
go to class
上课人数
class size
从八点起开始上课。
Class starts at 8 o'clock.
他没有来上课。
He wasn't in class.
他们在上课。
They're in class.
今天不上课。
There's no class today.
引申指一些教练、官员等的上任或被聘任。与“下课sense2”相对应to start work or be hired
教练即将上课，人们翘首以待。
The coach is about to start work to eager anticipation.
