1.to have a ball
例句：When the teacher had to leave the classroom suddenly, the children ended up having a ball.
2.The ball is in your court
例句：Once the citizens’ committee put forward their detailed views and ideas regarding the improvement of Public Transport in the city, the ball was in the Mayor’s court.
3.to get the ball rolling
例句：Once we received the approval from our boss, we got the ball rolling on our project.
例句：The actual cost of the project was far greater than the estimated ballpark figure.
5.Let’s play Ball
例句：Once I realized that my colleague was being highly competitive with me, I challenged him and said: “let’s play ball!”
例句：After a few meetings, I realized that the client was a complete Slime ball as he repeatedly lied and chose to inflate and brag about his non- existent achievements.
7.A different ball game
例句：As a manager managing a large team, keeping each team member motivated every day is a different ball game altogether.
8.A ball of fire
例句：The new employee we have hired is a ball of fire. He is always alert and energetic.
9.Eye on the ball
例句：When handling complicated tasks at work, it is important that everyone has their eye on the ball.
10.to drop the ball
例句：Our team ended up dropping the ball on an important pitch by being over confident and under prepared.