A peacock   and a tortoise   were good friends. One day, a bird catcher caught the peacock and was going to sell him on the market. The peacock asked the bird catcher to allow him to say goodbye to his friend the tortoise. The bird catcher agreed. The tortoise asked the bird catcher to let the peacock go, but he refused. The tortoise then said, "If I give you a nice gift, will you let my friend go?" "Certainly," answered the bird catcher. So the tortoise jumped into the river and after some time, he came up with a big pearl  . The bird catcher was so surprised. He was so happy that he let the peacock go. A few days later, the bird catcher came back to the tortoise. He thought he didn't get enough for letting the peacock go. He told the tortoise that he would catch the peacock again unless he got another big pearl. The tortoise knew his friend the peacock went to a safe place. "Well," said the tortoise, "please return the pearl that I gave you and I will come back with two." The bird catcher thought for some time and gave the pearl to the tortoise. Then the tortoise swam away and said, "I am not so stupid to take one and give two!" The bird catcher could only stand by the river and feel sorry for being greedy  . The passage mainly tells us   _  .
we shouldn't be greedy tortoises are clever animals we should be friendly to animals two different animals can be good friends