Patience is a virtue.
小洞不补，大来吃苦 A stitch in time saves nine.
工欲善其事，必先利其器 Sharp tools make good work.
己所不欲勿施于人
Do unto others as you would be done.
亡羊补牢
Better late than never./ It's never too late to mend.
上气不接下气
I got out of breath when I climbed those stairs.
寸步不离
He always keeps book at his elbow. (keep close to)
口若悬河
He always talks nine words at once. (rattle on)
仁者无敌
The benevolent have no enemy.
口是心非
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He often speaks with his tongue in his cheek. (play a double game; say one thing and mean another )
不可一世
I really don't know why she is always as proud as a peacock.
不可救药
His deep-rooted bad habits are simply beyond remedy.
不由自主
in spite of oneself：He is often absent-minded and dozed off in spite of himself in class.
不自量力
If he does so, he really goes beyond his depth. No one can beat that guy. (overrate one's abilities)
不屈不挠
Although he has failed several times, he still keeps his chin up. (as steady as a rock; firm and unyielding; fight for tooth and nail; hang on by the eyelashes; stick to one's color)
不知死活
John is really heedless of consequences. I believe some day he will ask for trouble.
不知好歹
Take my advice into consideration. Don't know chalk from cheese.
不耻下问
To improve your studies, you got to be not above asking questions.
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不假思索
He is good at speech. He often speaks impromptu.
不偏不倚
You should believe that the judge held the scales even. 不期而遇
I came across an old friend of mine in a department store. (chance to meet，bump into，come upon，meet...accidentally/unexpectedly/by chance/by accident)
不速之客
You are really a thick-skinned and gate-crasher.
不义之财
Don't be envious. Ill-gotten money comes easily and goes easily too.
不谋而合
see eye to eye：Do you see eye to eye with him on that plan?
不厌其烦
takes the trouble：The teacher often takes the trouble to instruct his pupils.
不遗余力
But the conspirators leave no avenue unexplored to re-establish contact with Britain.
不择手段
by hook or by crook：He just did the work by hook or by crook.
不翼而飞
Did you see that plane? It seems that it just vanished from sight.
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不声不响
as quiet/silent/still as a mouse：She was as quiet/silent/still as a mouse and left.
不识抬举
Bring a cow to the hall and she will run to the byre. (fail to appreciate sb's kindness/not know how to appreciate favor)
口蜜腹剑
A honey tongue, a heart of gall. ( be nasty-nice; Bees that have honey in their mouths have stings in their tails. )
久别情疏
Out of sight, out of mind. (Far from eye, far from heart. Long absent, soon forgotten. Seldom seen, soon forgotten.)
不告而别 French leave
不要不自量力
Don't put a quarter into a pint pot.
不要厚此薄彼
Don't make fish of one and flesh of another.
不畏艰难
Take the bull by the horns.
不战而屈人之兵
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The supreme art of war is to subdue the enemy without fighting.
不入虎穴焉得虎子
How can one obtain tiger-cubs without entering the tiger's lair.
不经一事，不长一智
Experience is the mother of wisdom.
不胜其烦
a pain in the neck：Your little brother is a pain in the neck.
心正不怕雷打
A good conscience is a soft pillow.
心甘情愿
He did all this of his own accord.
心不在焉
You look absent-minded; what's wrong?
心满意足
The little boy sat there smiling, as happy as a clam.
心力交瘁
I don't know what to do. I just burned the candle at both ends.
心灰意冷
He was in black despair when he failed in the joint examination.(down in the bushes/in the dumps/lose heart)
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