To be on the ball 机灵高效的
Rob: Hello and welcome to Authentic Real English. I'm Rob and joining me today is Liz.
Li: Hi… everyone – err, Rob, my name is Li, not Liz.
Rob: Oh, I'm so sorry Li, I'm not really on the ball this morning.
Li: Nice phrase though. Why don't you go for a coffee and then you will be on the ball for today's Authentic Real English?
(A little later)
Rob: Right, oh, lovely. That's better. I've had a nice cup of coffee and I'm ready to explain the meaning of today's Authentic Real English. Here you go. When you are on the ball it means you're alert and quick to react to things.
Li: 是的。To be on the ball 意思是机警，机灵，往往形容一个人对事物反应迅速。Ball 的单独意思是球。这个短语是不是从体育运动而来？It comes from sports, doesn't it?
Rob: Yes it does. And there is another phrase: 'to keep your eye on the ball' which has a very similar meaning.
Li: I guess we can use it for any situation which is changing quickly so that you need to be focused and sharp. 我们可以用这个短语来表示各种迅速变化的情况，看看你是否精神集中和思维敏捷。
Rob: Indeed. Let's hear some examples:
The interviewer raised tough questions but Ma Yun was on the ball.
Financial management is not a job that everyone can do. You have to keep your eye on the ball at all times.
Li: And if you want to learn English well you can stay on the ball with bbcukchina.com.
Rob: Also www.bbcukchina.com/learningenglish! Best of luck!
Li: Bye bye.