Teenagers are known for being creative and full of new ideas. Let's have a look at these teenage inventions that might change the world.

    No Car Day first started by 34 cities in France on September 22, 1998. People started it to protect the environment. By now, more than 1,000 cities around the world have a No Car Day.

    The first No Car Day in China was in Chengdu in 2001. Other cities, including Taipei, Shanghai and Wuhan, also support(支持) the day.

    In Beijing, more and more people are joining in the program. It asks drivers to leave their cars at home for one day each month and walk or ride a bike to work. It also calls on Beijingers not to use cars on June 5(World Environment Day). The slogan(口号) for the day is, "If we drive for one less day, we can have one more nice day."

    So far, more than 200,000 drivers Show their support. "We can't decide the weather, but we can choose not to drive," said Wu Zhonghua, a car dub manager. Beijing is trying to have 238 blue sky days this year. In the first quarter of 2017, Beijing only had 52 blue sky days. This was 11 days less than the number for the same period the year before.

    We must do more for No Car Day.

    As everyone knows, animals are our friends. Of all the animals, dogs are friendly to 1.

    Dogs are always staying 2 human beings. They are in different colours. There are many different 3 of dogs. Hunting dogs can 4people get more prey(猎物). The seeing-eye dogs can help 5people a lot. The police dogs can help the police.

    Today it is 6 to imagine the life without dogs. Maybe everyone is happy to see dog. Dogs are good at7 and smelling. Some dogs can find the people who are trapped(困) 8 the broken house. Some dogs can help take care of the houses. 9someone strange comes close to the house, they will bark to frighten him. Even some dogs can help look after kids when their 10 are not at home.

    In a word, dogs are our best friends among all animals.

    I'm sure you all know how important recycling is. Recycling is when you take old things and turn them into new things. It sounds like magic. But it's actually very scientific.

    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 needed. We know all living things are sure to die without food. In every part of the world, different kinds of animals share living places and live in communities (群落) together. They are connected(联系) in a food chain.

    In a food chain, some living things are producers and some are consumers. 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 world. 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 plants and animals. A scavenger is an animal that eats dead animal.

    Here is a picture of a food chain. The food chain shows how animal eat each other in a community. In the picture, you can see what animal or plant is food for another animal. See? The grass is food for a rabbit(兔子), which then becomes food for a hungry tiger. In this way, all of these animals are connected.