一心不可二用。
No man is born wise or learned.
没有生而知之者。
No man is content.
人心不足蛇吞象。
No man is wise at all times.
聪明一世，糊涂一时。
None are so blind as those who won't see.
视而不见。
None are so deaf as those who won't hear.
充耳不闻。
No news is good news.
没有消息就是好消息。
No one can call back yesterday.
昨日不会重现。
No pains, no gains.
没有付出就没有收获。
No pleasure without pain.
没有苦就没有乐。
No rose without a thorn.
没有不带刺的玫瑰。
No sweet without sweat.
先苦后甜。
No smoke without fire.
无风不起浪。
Nothing brave, nothing have.
不入虎穴，焉得虎子。
Nothing dries sooner than a tear.
眼泪干得最快。
Nothing in the world is difficult for one who sets his mind to it.
世上无难事，只怕有心人。
Nothing is difficult to the man who will try.
世上无难事，只要肯登攀。
Nothing seek, nothing find.
没有追求就没有收获。
Nothing is so necessary for travelers as languages.
外出旅行，语言最要紧。
Nothing is to be got without pains but poverty.
世上唯有贫穷可以不劳而获。
Not to advance is to go back.
不进则退。
Not to know what happened before one was born is always to be a child.
不懂世故，幼稚可笑。
No way is impossible to courage.
勇者无惧。
Obedience is the first duty of a soldier.
军人以服从命令为天职。
Observation is the best teacher.
观察是最好的老师。
Offense is the best defense.
进攻是最好的防御。
Old friends and old wines are best.
陈酒味醇，老友情深。
Old sin makes new shame.
一失足成千古恨。
Once a man and twice a child.
一次老，两次小。
Once a thief, always a thief.
剩下就不复制了,要知道我也是很懒的也很忙，楼主可以去看看参考资料：
http://www.hrexam.com/proverb.htm