►含义To be fully aware and in control of a situation.清楚局势，并能够把控局面。 ►例句 I didn't sleep well last night and I'm not really on the ball today.我昨晚没睡好，所以今天我有点大脑短路。 ►对话A:Fred is the best person for the job.弗雷德是这份工作的最佳人选。B:I agree with you. He is always on the ball and works really well under pressure.我同意，他总是很清楚局势，并且在压力下优秀地工作。 ►额外收获：1.be fully aware of: 对…有充分认识2.be in control of：掌控3.under pressure：在压力下