The boy and the girl in the picture sat on a bench talking merrily while eating a water-melon. When they went away they left the melon’s skin on the bench, making it very dirty. They didn’t want to take any trouble to throw it into the dustbin although it was very near where they were sitting. Instead, they said that there would be someone who should clean the rubbish.

　　However, what they did makes others look down upon them. If everyone behaves in this way, the world will be a big rubbish dump with flies flying round and people will live in a world of diseases. Besides, it will be impossible for dustmen to clean the world woth such people living in it.