We sometimes say the lion is "the king of the forest" because it is stronger and more dangerous than the other animals. It can run faster than most other animals and it can hunt other beasts. It is said that the lion is the highest animal in the land food chain（链）. In the sea, people say the shark is at the top of the food chain . It can swim faster than most of the other sea animals. It can also use its sharp teeth to catch other sea animals and eat them.
What is at the top of the world's food chain? Human beings! We are not the biggest or fastest, but we are the cleverest. We could not run faster than most animals, so we invented cars. We could not fight better than a lion
People's inventions are clever, but they can be dangerous, too. For example, people used guns to kill a lot of wild wolves. People thought they posed a threat to their sheep. But in recent years, the number of wild rabbits is becoming larger and larger because the number of wild wolves is getting smaller and smaller. The wild rabbits competed for the grass with the sheep and the cows, much of the grassland became desert because it was seriously destroyed by the wild rabbits.
Remember that we are a part of the food chain, so we are in danger, too! If we protect animals, we are protecting ourselves.
