during the late years of the qi dynasty(221-206bc), xiang yu led a rebellion. after crossing the zhang river, xiang yu ordered his men to sink all their boats and break their cooking pots.
he issued each soldier three days' rations(给养) and warned them that there was no way to retreat; the only thing they could do to survive was to advance and fight.
after mine fierce battles, the qin army was finally defeated.
this idiom is used to indicate one's firm determination to achieve one's goal at any cost.
Yan Jian was the regent(摄政王) of the last king of Northern Zhou(557-581).
His wife advised him: "Northern Zhou is dying. Now it is as if you are riding on the back of a tiger. It will be dangerous to dismount(下马，下车) . You can do nothing but continue."
Yan Jian thought this quite reasonable. Later, he founded the Sui Dynasty, and united China once more.
This idom is used as a metaphor meaning that one is in a difficult situation and cannot help but ontinue to pursue one's sourse.
In the Song Dynasty(960-1279) there was a joker called Sun Shan.
One year he went to take the imperial examination, and came bottom of the list of successful candidates. Back in his hometown, one of his neighbours asked him whether the neighbour's son had also passed.
Sun Shan said, with a smile: "Sun Shan was the last on the list, your son came after Sun Shan."
Later, people used this idiom to indicate failing in an examination or competition.
In ancient times there were no donkeys in Guizhou province. Somebody brought a donkey from somewhere and tied it to a tree at the foot of a mountain.
A tiger saw the donkey, and thought that it must be a fearsome(可怕的) monster. It hide behind a tree and spied on the donkey.
When the donkey brayed(叫) , the tiger was frightened, thinking that the donkey was about to devour(吞食，古诗词大全，毁灭) it. After a while, seeing that the donkey had not moved, the tiger approached it and teased it. The donkey became angry, and kicked the tiger.
The tiger thought to itself: "Its then all it is capable of?" It then jumped on the donkey and ate it.
This idiom is used to mean that one has exhauseted one's skills.，情书大全