Air pollution influences our health in many ways. No air means death. Though we can't see it, there is air around us. Air is everywhere and it gives a life to every living things. But bad air makes people ill. In the city, there are a great many people and there are too many cars running on the road. The cars send out bad gases (气体). There are many factories too. From the chimneys (烟卤) of these factories, we get the smoke usually in black colour. Every day we breathe it in and out. This makes us feel sick. When people talk about air pollution, they are usually thinking about outdoor air pollution. But a lot of air pollution comes from indoor activities such as smoking and cooking. Indoor air pollution can hurt people's eyes, noses and throats. So air pollution, both indoor and outdoor, can also lead to lung cancer (肺癌) and heart disease.

    Everyone should help fight against pollution. In order to keep us healthy, we have to go out to the countryside to breathe more fresh air. Or we can climb up hills to get more fresh air.

Nowadays Dianzan is one of the most popular words on the Internet. When you think someone's ideas are right, when you think someone's articles are 1, or when you are moved by what someone writes, you can click(点击) the praise sign. Anyhow, clicking the praise sign 2 that you agree with someone or praise someone.

Dianzan is a kind of Chinese Internet language. People 3use it when they surf the Internet. There is a function of Dianzan in the QQ space. The QQ space has had the function 4 2010. It didn't become very popular until Sina blog(新浪博客)5the function of Dianzan. In recent years, it has become more and more popular. When the 2015 New Year came, Chinese president used the word Dianzan to praise and express his 6 to the great Chinese people.

Websites can know how many people support some ideas by 7 how many people click the praise sign. Experts(专家) can know 8 teenagers are caring about through what they click the sign for. That can help them solve teenagers' 9.

Clicking the praise sign is really a(n) 10 thing. Have you ever clicked the sign for anybody on the Internet?

Astronauts would face dangers both getting to and surviving (生存) on Mars. Let's learn about surviving a trip to Mars.

What would it take to keep people safe and healthy on a trip to Mars? Scientists are already working on it, though the trip may be many years later.

Over the last 60 years, many spaceships have flown by orbited（沿轨道运行）and even landed on the Red Planet. However, machines cannot replace humans. That's why the United States, China and other countries want to send people to Mars. But surviving on this trip would not be easy.

A trip to Mars would be the farthest journey in human(人类) history. Mars is about 225 million kilometers away, so it would take astronauts at least 180 days to reach there. However, it only takes a few days to get to the Moon.

Space travel is dangerous. For one thing, staying in space for long periods makes the human body weak. Also, it puts pressure behind the eyes and causes eye problems. But gravity(重力) machines could help.

Then there's space radiation(辐射) to worry about. It is bad for astronauts when they have long journeys. Scientists are working out the issue. They have found that taking certain vitamins can help.

Astronauts will have to pack light to lift off from the earth. But they won't be able to get the things they need easily. Astronauts on the space station practice for this by growing lettuce and other food in space. Engineers are developing 3D printing techniques（技术）which can allow future Mars astronauts to build what they want.

After a relaxing weekend, children have to go back to school on Mondays. For parents, they should do something helpful (有帮助的) to let their children get to school on time.

Let children take a good shower. It's good for children to take a shower before they go to bed. It can not only help them sleep well but also save time next morning.

Ask children to go to bed early. School starts at 8：00 a.m. So please let your children go to bed before 9：30 p.m. Your children should (应该) sleep for about nine hours every day. This is quite important because they have to get up early next day.

Make a good breakfast for children. Breakfast can help children study better (更好的) in the day. It can help students listen to teachers carefully (细致地) and think well in class. Also, it's good for their health.

Getting to school on time is very important for your children. So please help them. If you can do the things above (以上), they will study and live happily.

It is one of the most famous books in the world; yet it has no story and no interesting characters, no exciting beginning and no satisfying ending. And yet it keeps being printed-and it keeps growing!

It began in 1857 as just an idea of a group of people who thought the world needed one to show the history of English words from 1150 CE to the present. It wasn't until the late 1870s, however, when James Murray joined the project that it began to grow. He planned one of about 6,400 pages in four volumes(卷),completed in 10 years. He did most of his work in a small building where he and his workmates collected millions of pieces of paper, each one with a word and an example sentence written on it. Murray and his workmates worked hard, but after five years they had only reached the word ant! It was until 1928 that it was completed and came out. Unluckily, Murray did not live to see the completion of his life's work; he passed away in 1915. As soon as it came out, people started to update it. In 1933, it became 12 volumes. Between 1972 and 1986, four more volumes were added. In 2020 it was reprinted in 20 volumes. Three years later, all the volumes were put onto CD-ROM, and it can be bought online at present.

It not only is a record of where the English language has come from but also become an important part of the history of English-speaking cultures around the world.

Deadly flooding has swept China s northern provinces this summer，causing many losses such as a number of people died and houses were destroyed（破坏） by floods. Like many other natural disasters，floods can happen with little or no warming. Finish floods move quickly and have strong currents（水流）. They are known to bring down trees and take down buildings. Besides，floods can cause power cuts （停电），traffic jam and other problems. But the food itself isn't the only problem to deal with. After the flood，it may have deadly results，as it may not be easy to send food and water to the area. 

So In the face of a flash food，how should we save ourselves？

*Don't use bridges that rapidly﹣moving water is crossing，as floodwater can cause bridges to break. 

*Listen to emergency broadcasts （应急广播） for more information. If told to move to another place，do so. 

*Stay inside the car if the car Is caught in the fast﹣moving water. Only get out if the water begins to food the car itself，and then move to the roof（项部） of the car. 

*Stay away from power lines （电线），as they are knocked down during the strong storms. Besides，here is something to keep in mind after a flood. 

*Do not use floodwater to wash food or drink it. 

*Return to your home only after the government has said it is safe to do so. 

*Use only bottled or clean water for drinking cooking are nothing.