on the ball

機警；警覺；有把握

Thanks for pointing that out； you‘re on the ball this morning.

謝謝你指出了這一點，你今天上午很機敏。

ball

英 [bɔːl] 美 [bɔl]

n. 球；舞會

v. 成團塊；捏成球形

（尤指盛大或正式的）舞會

You are invited to the Christmas Ball.

你被邀請參加圣誕舞會。

彈丸 【射擊】

He was seriously wounded by a ball in the chest.

他胸部中彈，受了重傷。

have a ball

盡情歡樂；玩得很開心

Judging by the gales of laughter， they were having a ball.

從陣陣笑聲來看，他們玩得很盡興。

keep the ball rolling

把某事繼續下去

Somebody has to keep the ball rolling to get the peace initiative moving.

必須有人持續跟進，以便啟動和平行動計劃。

play ball

合作

Play ball and agree to the peace plan or condemn your people to poverty and war.

要麼進行合作，同意和平計劃；要麼讓你們的人民陷入貧困和戰爭。

play ball with sb

與某人合作

We‘ll look after you if you play ball with us on this case.

如果你在這個案子上與我們合作，我們會關照你的。

vi 呈球狀；成團塊

His fists balled in his lap.

他雙手握拳，放在大腿上。

ball多指社交性的舞會，場面較為隆重和正式

dance指一般性的非正式舞會