1、She is driven by necessity to steal food for her starving children.
環(huán)境逼得她為挨餓的兒女偷竊食物。

2、Many people, either by necessity or by choice, don't get as much sleep as researchers recommend.
很多人，或者是生活所迫，或者是自己的決擇，并沒有像研究者所推崇的那樣睡那么多覺(的的確確，包括作者本人)。

3、determined by chance or impulse or whim rather than by necessity or reason.
根據(jù)偶然性、沖動或者一時(shí)的興致來決定而不是根據(jù)必要性和理智。

4、She was driven by necessity to steal food for her starving children.
她是迫不得已才為她饑餓的孩子們偷食品的。

by necessity翻譯