There are many wetlands(湿地)in China and some of them have become the world's important wetlands. The Chinese Yellow Sea Wetlands are among them. They are in Yancheng, Jiangsu Province. They are home for many different kinds of birds and animals. The world's largest Milu Deer Nature Reserve(自然保护区) is in them. More than 700 milu deer live freely there. In winter you can see some red-crowned cranes in the Yellow Sea Wetlands though there are not many in the world.

It is not too hot nor too cold in the wetlands. There is a lot of rain and sunshine, too. They are really good places for wildlife. Offering food and home for some special kinds of animals and birds is not the only reason why we need to protect wetlands. Wetlands are important because they also prevent flood(洪水). But some people want to change the wetlands to make more farms and buildings. This means there will be less and less space for wildlife.

    Luckily, more and more people are beginning to realize the importance of wetlands and wildlife. Every year, on February 2nd, many activities are held to tell people more about wetlands.

A

    Everyone knows that exercise is important. It makes your heart and body strong. But you need to know the following.

*Get your body ready!

    Before you do any exercise, be sure to warm up for at least five minutes. During warming up, you should stretch(伸展) all parts of your body.

*Exercise enough, but not too much.

    It's good to exercise twice each week. Thirty minutes each time is enough. Try all kinds of things until you find one, two or even three sports that are right for you.

*Exercise at fitness centres.

    There is a lot of equipment(设备) at fitness centres. The equipment will help exercise your arms, legs and other parts of your body to make you fit. Some people buy equipment. But it is very expensive.

*Stop playing when you are hurt!

    If you get hurt when you are doing exercise, don't play again until you are well.

*Don't get thirsty!

    Drink a lot of water when you are playing sports because it is easy to become thirsty.

    Both seasonal flu, a disease like a very bad cold, and much larger pandemics, like the one caused by H7N9（禽流感） in 2013, are the result of a race between the flu virus  and the immune system which can protect people from illness. Here's how it works.

    Viruses, which cause pandemics, have two important proteins "haemagglutinin(H) and neuraminidase(N).H helps the virus go into a cell .N helps new virus break out of that cell .They are parts of a virus that may be known and dealt with by the immune system

    A flu virus attacks a host cell in order to reproduce itself. But the virus created out of it is quite different now. The virus's genetic material is copied with low fidelity. That difference produces virus which immune system does not always know and deal with immediately. Each year's seasonal virus is therefore a little bit different, and thus requires an updated vaccine to prevent people from getting that disease.

    Pandemics viruses have bigger changes in this process .Many hosts' defences are unprepared for such big changes, which happen three or four times a century .The 1918 pandemics was caused by viruses carrying H1 and N1.Anotber two pandemics in 1957 and 1968 were caused by viruses carrying H2and H3 together with N2.They are numbered by scientists. Much of this change goes on outside humans. A flu is usually from sick binds. Sometimes a bird-flu appears with materiel that enable it to spread among people .The H7N9 is recently worrying scientists in the health center.

    The flu virus sometimes jumps directly from a bird(often a chicken) to a person, but more usually passes through a pig The cells in bird and human are built differently, It means us that the virus needs different sets of material to attack them .Pig cells have features of both so that it can act as a platform in which the virus can fit from one to the other .Even after it has made humans ill, a virus cannot go ca to cause a pandemic unless it also gets the ability to pus easily between people, Luckily, this is something H7N9 has yet to do.

    Cars make our lives more convenient. But they can also be a problem. For example, fossil fuel(化石燃料) cars mainly cause air pollution.

    To improve the environment, many countries are developing electric vehicles(EVs，电动车). Among them, China is' taking a leading role and has created the world's largest EV market.

    Last year, over 40 percent of the 753, 000 EVs sold in the world were sold in China, more than twice as large as the number sold in the United States.

    "Filling up a fossil fuel car with gas is more expensive than charging an electric car," said Wu Hao, who bought an electric car this year.

    However, there are still some problems. It can be hard to find charging piles and the cars can't go far before needing to be recharged.

    Some of these problems are being solved. In 2014, China had 31, 000 charging piles. Now China has the world's largest EV charging network, with more than 167，000 charging piles in total.

    Developing EVs is one of many efforts that China has made to cut down pressure on its environment after the government promised to stop increases in carbon dioxide emissions by 2030.

    "As China goes, so will the world's car industry," the Wall Street Journal said. China has taken a leading role in the world's electric vehicle industry.

    Have you ever been ill? When you are ill, your body becomes hot, and there are pains all over your body. You must be unhappy because of it. You don't want to work. You stay in bed feeling sad.

    What makes us ill? It's germs. Germs are everywhere. They are very small and you can't find them with your eyes, but you can see them with a microscope (显微镜). They are very, very small and there could be hundreds of them on a very small thing.

    Germs are always found in dirty water. When we look at dirty water under the microscope, we can see them in it. So your father and mother will not let you drink dirty water.

    Germs aren't found only in water. They are found in the air and dust (灰尘). If you cut your finger, and if some of the dust from the floor goes into the cut, some of the germs will go into your finger. Your finger will become big and red, and you will have much pain in it. Sometimes the germs will go into all of your body, and you will have pain everywhere.