谁知道on the ball的意思?

on the ball: vi. 警惕(知情)

Examples:
1. The great value of Jack as a committee man is that he is always on the ball.
作为一名委员，杰克的巨大作用是始终保持警惕。
2. The new publicity manager is really on the ball.
新的宣传部主任确实很内行.
3. If you don't get on the ball and start studying harder, you're going to flunk.
如果你不积极进取，更加努力学习，你就会考不及格的。
4. The new clerk is really on the ball. He's already improved the filling system in the office.
新来的办事员真能干，他已经改进了办公室文件归档的方法。

In class you must stay on the ball.:在班上，你必须积极进取／很能干．

1、在球上
2、在舞会上
3、在睾丸上
4、机警, 高明, 敏锐的

勤奋，机灵，留心，有见识

在舞会上

bu renshi