Once upon a time, a hippo(河马) lived in a river next to a big tree. One day, a bird came and nested(筑巢) in the tree. The songs of the bird filled the hippo with so much envy(羡慕) that he couldn't think of anything else. Every day he would think why he wasn't born to be a bird even though the bird told many times he was so lucky to be so big and such a good swimmer.
Finally, the hippo made up his mind that he would come out of the river, climb the tree, and start singing. However, when he tried to climb the tree, it was very clear that the hippo didn't have wings, nor claws to climb with. Realizing that he would never climb up the tree, he angrily hit the tree, and began singing. Unfortunately, hippos can't sing, either. All that came from his mouth were terrible noises, and when the other animals heard this, they all came around to make fun of the hippo.
He was so ashamed by this. He also felt bad about having knocked the tree over. He used all his strength to raise the tree back up again, and look after it until it completely recovered(恢复).
