我不确定该告诉爸爸什么——我只能见机行事了。

I'm not sure what to tell Dad - I'll just have to ___play ___it ___by ___ear.

在去剑桥的路上，我决定见机行事。

On the way to Cambridge, I had made up my mind to ___play ___it ___by ___ear.

既然天气如此多变，我们在计划户外活动时应该见机行事。

Since the weather is so changeable, we should ___play ___it ___by ___ear when planning our outdoor activities.