China has been divided into three kingdoms historically： Wei in the north, Shu in the southwest and Wu in the southeast.
历史上，中国曾被分为三国:北边是魏国，西南是蜀国，东南是吴国。
Once Cao Cao from Wei led a 200,000 strong army down to the south to wipe out the kingdoms of Wu and Shu.
有一次，魏国的曹操带了20万精兵南下攻打吴国和蜀国，准备消灭它们。
Therefore, Wu and Shu united to defend his attack.
为了应敌，吴国和蜀国结成同盟国。
Cao ordered his men to link up the boats by iron chains to form a bridge for the Cao’s passing from the north bank of Yangtze River to the south bank.
曹军驻扎在长江北岸。曹操让手下用铁链将战船连在一起，好渡江攻打南岸的吴蜀军。
The General Commander of the allied army was Zhou Yu.
联军主将为吴国将领周瑜，
He analyzed the situation carefully.
他仔细分析了形势，
Then he got a good idea. He decided to attack the enemy with fire,
最后决定用火攻。
so he began to prepare for the coming battle.
于是，他开始着手备战。
Suddenly he thought of the direction of wind.
这时他突然想到了风向问题。
He needed the east wind to blow strongly in order to accomplish hi scheme.
只有强劲的东风才能助他实现火攻之计。
However, the wind did not come for days.
可连续几天都没有东风，
Thus, Zhou Yu was worried a-bout it.
周瑜急得病倒了。
At that time, he got a note from Zhuge Liang, the military adviser of the State of Shu, which reads：
这时，蜀国的军师诸葛亮叫人送了一张纸条给他，上面写着：
“To fight Cao Cao Fire will help you win Everything is ready Except the east wind"
“要赢曹操， 须用火攻。万事倶备，只欠东风。”
Quickly he turned to Zhuge Liang for help.
周瑜收到后，立刻向诸葛亮求助。
Zhuge told him not to worry, and there would be an east wind in a couple of days.
诸葛亮叫周瑜不要着急，两天后，将有东风。
Sure enough, two days later, it blew the east wind,
果然，几天后，刮起东风。
taking the chance of it, Zhou Yu burnt all the warships of Cao.
周瑜趁这个机会将曹军的战船烧毁，
At last, the allied army won the war.
最后，吴蜀联军大获全胜。
Later，people use it to say “All is ready except what is crucial”.
后来，人们用这个成语来比喻样样都准备好了，只差最后一个重要条件。
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