A long, long time ago, during the Three Kingdoms period in China, there was a very clever general named Cao Cao. He led a large army on a long - distance march in the sweltering weather. The soldiers were extremely thirsty because they had been walking for a very long time and couldn't find any water sources around.
One by one, the soldiers were listless and their steps became heavier and heavier. They were both tired and thirsty, and some of them even began to be unable to move forward. Cao Cao was very worried when he saw this situation. He knew that if the soldiers continued like this, they might not be able to reach their destination.
Suddenly, Cao Cao had an inspiration. He rode on his horse, pointed forward with his finger and shouted loudly, "Soldiers, look! There is a large plum grove ahead. The plums in that grove are big and sour. As long as we get there, we can eat the plums to quench our thirst." When the soldiers heard Cao Cao's words, it seemed that the sour plums appeared in their minds, and saliva unconsciously secreted from their mouths. They didn't feel so thirsty anymore.
So, the soldiers regained their spirits, quickened their pace and marched forward in the direction Cao Cao pointed. In this way, Cao Cao used his wisdom to boost the morale of the soldiers, enabling them to overcome the difficulty of thirst and continue the march. Finally, they reached their destination successfully.
