As we know, all living things have to eat food. For a man, a tiger, a fish, a bird, or even a worm, food is necessary. Generally speaking, all living things are sure to die without food. In every part of the world, many different kinds of animals share living places and live in communities (群落) together. They are connected in a food chain (链).

 Within a food chain, some living things are producers and some are consumers (消费者). Plants are producers because they use sunlight, soil and other things to make their own food. Animals are consumers because they have to eat other animals or plants.

There are four different kinds of consumers in the animal kingdom. A carnivore is an animal that only eats other animals. An herbivore is an animal that only eats plants. An omnivore is an animal that eats both plants and animals. A scavenger is an animal that eats dead animals.

 Look at the picture. It is an example of a food chain. The food chain shows the order that animals eat each other in a community. In the picture, you can see what animal or plant is food for another animal. See? A leaf is food for a grasshopper, which then becomes food for a hungry mouse. The mouse is food for a snake. The snake is eaten by an eagle. In this way, all of these animals are connected.

根据上文内容判断正 ( T ) 误( F )

    There are many magic（神奇的) things in the world of animals. Please look at the followings：

Huge Waves Destroying Arctic Ice Faster than Expected

    Ice covers much of the Arctic Ocean (北冰洋). Some pieces of ice are huge, like moving islands. As temperatures have increased, however, some of the ice has begun to disappear. Scientists have discovered huge waves (海浪) in the arctic waters.

    The waves were discovered by accident in May, 2010. Scientist Aleksey Marchenko and his students set out on a trip. They wanted to study the icy waters.

    On May 2, the ship traveled east and stopped next to a large chunk of ice around 50 miles from the small island of Hopen. Marchenko prepared to lead his students out onto the ice.

    "We were ready to go but when I went out, I discovered many cracks (裂缝) around," he remembers.

    He decided to move the ship deeper into the ice to keep safe. The farther in they went, he thought, the harder the ice would become. As they pushed forward, however, the ship experienced small waves, and then bigger ones. Soon, the waves broke up the ice around the ship into thousands of smaller pieces.

    Within an hour, Marchenko and his team saw a wave that was about 13 feet high. The ship's navigation (航行) system finally recorded the largest waves. They were more than 20 feet in height. The waves were so strong that they forced huge pieces of ice to jump up and down, breaking the ice into smaller pieces within just one hour. Scientists had never imagined that the process could happen so fast. The waves in these areas used to be small.

    The speed and force of the huge waves there makes it impossible to know in advance when they are coming. That could be dangerous for navigators and local communities who are unprepared for huge waves or depend on sea ice to protect them. Wildlife like polar bears and walruses that depend on sea ice to live is also in danger.

    Some scientists think people will soon see even bigger waves in these icy waters. As waves break up ice, the seas will become more open, and the waves will get even stronger. There are stormy times ahead.