Garbage(垃圾) Island

    You can't see it from the air. It's almost impossible to see from a ship. But somewhere in the North Pacific is a huge island of garbage, just below the water surface.

    What is the island made of?

    The garbage island is not an island, but a collection of millions of plastic and other objects. The water movements of Pacific Ocean bring the objects together and cause them to go around in a big circle.

    Charles Moore found it in 1997 and named it “the Great Pacific Garbage Patch” .

    Where does all the plastic come from?

    Much of the garbage comes from everyday objects, such as shopping bags and water bottles. Some of these objects finally reach the ocean. Garbage from the western coast of North America takes about six years to reach it. Objects from East Asia take about a year. Other garbage comes from ships passing through the area.

    Is the Garbage Patch dangerous?

    The larger pieces of garbage are a problem for wildlife. For example, sea turtles（海龟）and seabirds often think the plastic is their food. They eat the plastic and die.

    In addition, the plastic stops sunlight from reaching deeper water. Without sunlight, very small sea animals die. Then, there is less food for larger fish to eat.

    What can we do to help stop it?

    Cleaning up the island isn't easy. But we can make people realize the problem. One environmentalist(环保主义者), David de Rothschild, is sailing around the world in boat made of plastic bottles to teach people about the problem of garbage in the sea.

    Another idea is that we can recycle the plastic garbage. Environmental engineer Cesar Harada is building a robot that collects pieces of plastic. Harada hopes to use his robot in the Pacific. Harada also has a website for reporting environmental problems. He says, “I hope everybody can become an environmental activist.”

    Traveling can be expensive. But there are some ways to save money when traveling.

Look for city tourism cards. With the card, you can pay less at restaurants and shops. You don't have to wait for a long time at busy attractions. You might even get free tickets to top tourist attractions.

    Don't get the best room. How long will you stay in your room? Will you just be sleeping there? Do you really need a bigger room with a good view? （景色）

Find a hotel outside a city. It can help you save money by choosing a hotel away from big tourist attractions.

    Book(预定) a room with a kitchen. Although some people might not like to cook while on vacation, I don't mind making breakfast in my room. I'd rather eat breakfast and lunch at the hotel and then spend much money on a delicious supper.

    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.

    Recently, many people have begun to try a new way of shopping through the Internet. They are very interested in it. Why is it becoming more and more popular now? There are some reasons. First, more and more people have their own computers and their computers can be joined with the Internet. So it is possible for many of them to do some shopping through the Internet. Second, shopping through the Internet can save some money and a lot of time. Third, they don't need to go to the shop themselves, Because of these good facts, few people refuse it.

However, some people don't like this new way of shopping. They are worried about the safety of shopping online, Customers can only see the pictures of a product on the Internet. And they can't enjoy the pleasure of buying things in a large supermarket or a wonderful shopping centre. These are the reasons why they do not like it.

    But I think more and more people will like this new kind of shopping in the future.

    In some science fiction movies, evil robots refuse to die, no matter how hard people fight back.

    Now science fiction has become science fact. For the first time, scientists have made a robot that can take a beating (挨打) and keep on going. Scientists from Cornell University made the robot, which looks like a spider with four legs.

    Until now, even the most advanced (先进的) robot was almost certain to break down when it was damaged. That is because its computer inside simply doesn't know how to make the machine work after its shape has changed.

    To deal with this problem, the scientists put eight motors (发动机) and two sensors (传感器) that read how the machine is working. They all give signals to the machine's software. Using this information, the computer can then figure out the machine's shape at any moment.

    The new technology is a big advance in robot-making, scientists say, and it's far from scary. It may someday help scientists create better artificial (假的) arms and legs and give new freedom to people who lose them. It might also help scientists understand how people and animals figure out their own sense of place in space.

    "It has been difficult to design robots that can work well when the environment changes or when it's damaged," says Olaf Sporns of Indiana University in US. "With this work, we are nearer to solving this problem."

    Gardening is popular in many parts of the world. It brings us sweet smelling flowers, fresh fruit and vegetables. But you can get more from your garden.

    Gardening helps to keep healthy. Today's people sit indoors for too long and don't get much exercise. When you garden, you have to move around. It's a good chance for you to exercise your body by watering flowers or doing some digging. Besides, when you are in your garden, you can feel the warm sunshine. This means you are getting Vitamin D. It helps your bodies use calcium (钙), which is necessary to keep your bones (骨骼) strong.

    It gets them off computers, televisions and phones. Gardening can be a great teacher to teach children about nature and healthy eating. It can also help them to understand the meaning of "No pains, no gains."

Gardening is a great way to meet people and build relationships. When you are gardening, you are outdoors. So it is a perfect time to communicate with your neighbors. Most people love to talk about their hobbies, and so do gardeners. They usually enjoy showing people what they are growing. And most enjoy sharing advice and stories about their gardens.