The courteous boy was civil to everybody.

这个谦恭男孩对每一个人都很有礼貌。

Being youngsters, we sat modestly at the back, never daring to speak.

我们些年轻人,都谦恭地坐后面,始终不敢发言。

I do apologize most humbly.

我非常谦恭地道歉。

He’s a real Jekyll and Hyde. At home he shouts at his wife and children all the time; at work he’s always charming and friendly.

他才个有双重性格人呢！冲着妻子儿女大喊大叫；上班时却总温良谦恭，和善友好。