就便的英文：
at somebody's convenience; while you're at it

to sit for somebody
为某人做临时保姆

fall to somebody by assignment or lot.
通过分配或者划分使某人垮台。

He is somebody in this city.
他在这个城市是个重要人物。

An apartment that is convenient to shopping and transportation.
购物和交通均很近便的公寓

The lower deck is more convenient.
下层甲板更方便些。

The terrace channels are convenient for irrigation.
梯田的沟渠便于灌溉。