Long long ago, a God called Ratu lived in the sky. Ratu liked to play games and make people angry. The game he liked best was to fly down into the sea and frighten all the fishes. The fishes became very tired of his game. They asked Hemi, the God of the sea, to help them. So Hemi tried to catch Ratu the next time he flew into the sea, but he was too slow. Ratu laughed at Hemi as he flew past him. This made Hemi angry and he had an idea. He asked the fishes to bring him a lot of seaweed. Hemi tied it all together and made a large net from it. Soon Ratu flew down and Hemi threw the net over him. Ratu fought and fought but could not get free. He was caught. Ratu promised   never to frighten fishes again if Hemi would set him free. But Hemi did not believe him. Instead, he changed Ratu into a mountain in the sea. Ratu was so angry that when he opened his mouth to shout at Hemi, fire and smoke broke out. And that is why the Island of Ratu is a volcano  . The key meaning of this story is   _  .
how volcanoes are born why the Island of Ratu is a volcano how Ratu was beaten why some gods are good and some are bad