我没时间来准备这次会议，我只能临场发挥了。

I don't know what to say when he comes, just play it by ear.

玛丽：这样的问题事先通常无法准备，只能临场发挥。

Mary: In this case, you should first keep calm and normal to the face.

这就对日程行为，判断和一般性的临场发挥也会产生不利的影响。

This has an adverse effect on the behavior, judgment and general performance.