We sometimes call the lion "the king of the jungle (丛林)" because it is stronger and more dangerous than other animals. It can run faster than many animals and it can hunt (捕猎) the best. It is the highest animal in the 1 food chain (食物链).
In the sea, the shark is one of the animals at the 2 of the food chain. It can swim faster than most other sea animals, and it can use its big teeth to eat them.
What is at the top of the world's food chain?3 are! We are not the biggest or fastest, but we are the 4 We could not run faster than cheetahs (猎豹), so we5 cars and now we can move the fastest. We could not 6 better than lions, so we invented guns (枪). Now we can hunt the best.
People's inventions are clever, but they can be dangerous, too. For example, people invented 7, and now they make the air and rivers dirty. This can make8 changes. Dirty rivers kill fish. Then bears cannot eat the fish and the bears die. If we kill one part of the food chain, 9 also die. Remember that we are a part of the food chain, so we are in danger too! If we protect animals, we are protecting 10! We should and we could do something for the world!
Many animals hide to stay alive. They hide in many ways. Some animals hide in leaves; some animals hide in snow. Usually their colors or shapes help protect them. It's hard to see an Arctic bear in snow. Its white fur helps protect it. Chameleons(变色龙) can hide by changing colors. Their skin turns the same color as what is around them. Some chameleons can change colors in five minutes.
Many animals try to look bigger than they are to stay alive. Some animals can make other animals think they are very big. If they look very big, animals that are looking for food will run away. Bears can walk on two legs. They look very, very scary. Some animals will run away from them.
Many animals try to stay around other animals. This helps them stay alive. Zebras stay close together so that they can help each other look out of danger. Seeing many stripes at once can also confuse animals that want to eat them. Some birds stay in a circle, each toward a different direction. In this way they can also help each other stay alive by looking around for animals that many want to eat one of them.
