Do you know 3-D printing? It is very new and is developing fast all over the world. With its help, people can print real world things with a 3-D printer. People believe it will have a very great future. 3-D printers seem to be able to make many things in just a short time.

   However, 3-D printing is still a little expensive for everyday use, but we believe we will have personal 3-D printers in the near future.

   Many people are dreaming even bigger, and it seems that if you can imagine it, you can 3-D print it. If not now, then will be soon. Look, some people already have exciting imaginations!

Some toy companies are working on helping kids imagine their toys and then printing them. And there are already 3-D printed candies! A company inChinaeven built 10 houses in Shanghai in one day with a large 3-D printer. Are they the most comfortable homes? No. But they could help the homeless people a lot. These houses didn’t cost much (each house cost about $5,000). It’s a cheap and very environmentally (环保的) friendly way to build houses.

   North American black bears are shy animals. They are fearful by nature, and will usually run away if they see or hear people. Because of this, it can be difficult for scientists to learn about these animals.

   In order to study black bears, researchers from New Jersey, USA, catch bears and use drugs to help them go to sleep. Researchers then work out the size and the weight of the bear, take blood to test for diseases, remove a tooth and take it to the lab to find out its age. From these studies, researchers want to find out how many bears live in New Jersey, how long they live, and how many babies they produce.

   But in Minnesota, USA, researchers study bears that are completely awake. The bears know the researchers' voices and they aren't afraid of the research team. With the help of a few grapes to keep the bears busy, researchers can touch them to check their hearts, look at their teeth, and do other jobs. Researchers can also walk or sit with bears for hours and make videos to learn about their everyday lives.

   In both places, the main purpose is the same--to make sure there is a healthy population of black bears. But the research ways and the kinds of information that researchers are able to collect are quite different.

What will the weather be like? Some people say they can know what the weather will be like from birds. They kook at birds. When they see birds fly high out to the sea, they say it will be a nice day. For birds donˈt like to fly out when it could rain. When the weather will be bad, sea birds turn back and stay on shore.

A big wind may come with a rain. Birds do not like to fly in a big wind. They may sit in a tree when rain is on the way.

Some people look at different animals on a farm. Other animals can alsotellthe weather. A chicken may make a big noise when rain is on the way. It may run here and there. A frog can show the weather, too. A frog will make a big noise when rain is on the way. It will stay in the water. On a nice day, it will come out up high out of the water.

Learning about the environment is very important. There are many good books that will help you learn. To get started, ask your teacher or a librarian for some suggestions. You can also look at some good websites(网站) with information about the environment and climate change. Climate change may be a big problem, but there are many little things we can do to make a difference.

Driving a car or using electricity is not wrong. We just have to be smart about it. Some people use less energy by carpooling. For example, four people can ride together in one car instead of driving four cars to work. Whenever we use electricity, we put greenhouse gases into the air. By turning off lights, the television and the computer when they aren’t needed, you can help a lot.

Don’t buy products that use too much energy. Some products, like certain cars, are made specially to save energy. These don’t pollute as much, either. Products like computers, TVs, and VCRs with the ENERGY STAR label(标签)R are made to save energy. Buying products with these labels will help protect the environment.

Buy recyclable products instead of (代替) non-recyclable ones. Recyclable products are usually made out of things that have already been used. It usually takes less energy to make recyclable products than to make new ones. So when you go shopping, look for the recycle mark on the package—three arrows that make a circle.The less energy we use, the better.

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  Many people travel to different places in the world by air. Usually it takes a long time, perhaps half a day, for passengers to stay in the plane. So airlines, offer passengers food. But it is common that they feel bad about food taste. Do you agree?

   To solve this problem, airlines try hard to improve their food. They would like to do so because they don't want to lose customers.

   However, according to scientific research, part of the reason why plane food tastes bad is that at high "altitude (海拔) we can not taste things as well as we do on the ground. Also scientists have found that our noses become very dry even before a plane takes off. As the plane moves up, the change in air pressure reduces one third of the sensibility (感觉) of our taste buds (味蕾). So our taste buds become senseless. The sad face, however, is that our noses don't know it.

   All of these help explain why food on the plane tastes so bad. They also help explain why airlines choose to offer passengers salty and spicy food. Without doing so, the food would be tasteless.

   Now there are many researches on this, According to one of them, some volunteers are asked to lie with their feet higher than their heads for weeks. And scientists write down their feelings about food taste.

   Though scientists try. their best, it is not as easy as they thought. Because they can't deal with the special environment successfully, such as the change in air pressure, making food taste good is still hard for them.

  Many people like to travel by plane, but I don’t like it because an airport is usually far from the city. You have to get there early and wait for hours for the plane to take off and it is often late. On the plane you can’t open the windows or choose (选择) the food. Planes are fast, but it usually takes people hours to go out of the airport and into the city.

   I like traveling by train. I think trains are safe. Railway stations are usually in cities. When you are late for a train, you can catch another one. You can walk around in the train and open the windows. You can see many interesting things on your way. I know it takes a little more time.

   I also like cars. You can start your journey (旅行) whenever you want to, and you needn’t get to a railway station or a bus stop. Also you can carry many things with you in a car. But sometimes there are too many cars at rush hours (高峰期) on the road and you have to move very slowly.                 

It is important to learn about protecting our environment. Here are 5R rules for us:

1Reduce

If you want to reduce the waste, you should use things wisely. People are cutting down millions of trees to make paper. If everyone uses paper carelessly and throws it out, soon we will not have any trees left. We are also wasting other things and don’t know how to deal with the waste in big cities, so it is necessary to reduce the waste.

2Reuse

You should always think of reusing the things before throwing them away. Give your used clothes or small ones to the poor. In a family, you may pass on such clothes to younger brothers or sisters.

3Recycle

We can recycle bottles, cans and paper easily. By doing this we save lots of time and money. For example, we can send waste Coke cans to a factory. And they are used to be made into new things by the workers.

4Recover

When you buy a box of apples, there may be a few rotten (腐烂的) ones. You have two choices: to throw the whole apples away, or to cut off the rotten parts and eat the good parts. In the second way, you are recovering the eatable parts of food.

5Repair

If one of the legs of your table is broken, you can repair it instead of throwing the table away. If you want to change for better ones, it is better for you to sell the old things or give them to other people who can use them after doing some repair. It is true thatNorth Americais a “throw-away” society, but the time has come to change our way of life so that we can protect our environment. We should try our best.

Many people like to search the Interact. Searching the Interact is one of the most important activities of a day. The Internet makes the outside world closer to people's homes. Some people say the world is smaller than before because of the Interact.

   What's going on in other countries? How do people live in places far away? Is there a good sports game somewhere? What's the life like in the deepest part of the sea? If you want to answer all these questions, just come to the Interact. Of course, people can also learn through reading or listening to the radio. But with the Interact they can learn better and more easily. A lot of information can be collected at a great speed.

   Can we go shopping without leaving home? Can we see a doctor without going to a hospital? Can we study without going to school? Can we draw money without going to the bank? All these things seemed to be impossible, but now they have become quite possible.

   The Interact helps us open our eyes and our minds. The internet often gives us new ideas. In a word, it helps us in many ways. Great changes have taken place in our life since the appearance of the Interact.

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he world is not hungry, but it is thirsty. It seems strange that nearly 3/4 of the earth is covered with water while we say we are short of(短缺)water. Why? Because about 97% of water on the earth is sea water which we can’t drink or use for watering plants directly. Man can only drink and use the 3%--- the water that comes from rivers and lakes. And we can’t even use all of that, because some of it has been polluted.

Now more water is needed. The problem is: Can we avoid a serious water shortage(短缺)later on?

First we should all learn how to save water. Secondly, we should find out the ways to reuse it. Scientists have always been making studies in the field. Today, in most large cities water is used only once and then runs to the sea or rivers. But it can be used again. Even if every large city reused its water, still there would not be enough. What could people turn to next?

The sea seems to have the best answer. There is a lot of water in the sea. All that needs to be done is to get the salt out of the sea water. This is expensive, but it’s already used in many parts of the world. Scientists are trying to find a cheaper way of doing it. So you see, if we can find a way out, we’ll be in no danger of drying up.

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Do you know plants can help people work better? Studies show that keeping plants in workplaces can help people work better.

To help students work better, some schools also keep some plants in the classrooms. These plants have a part to play in the classrooms. They help students concentrate (集中注意力) in class so that students can learn new things and get information more easily. It’s especially good for children to listen to the teachers carefully. Students sometimes think that the lesson is boring, and they don’t want to sit there. Keeping plants in the classrooms can be a great help to students. It can help students stay in the classroom longer and help them concentrate.

We all know that plants can offer  us food and clean air, but today we know that plants can also play an important part in our work and our studies. Just keep some plants in your work or study place. They can help you work better.