give thought to: 想，考虑
Let the wise give thought to these things, and see the mercies of the Lord.
凡有智慧的、必在这些事上留心．也必思想耶和华的慈爱。
I hope you give a second think to our counter offer.
我希望贵方重新考虑一下我们的还盘。

play it by ear: 见机行事
Just play it by ear.
只要随机应变就是了.
I haven't decided what to say when he comes; I'll play it by ear.
他来时我不知道该说什么,到时候随机应变吧.

on earth: 究竟，到底
What on earth had possessed her to agree to marry him?
究竟是什么让她同意嫁给他的？
What on earth is the matter there?
那里究竟发生了什么事情?