The leaders （领导人） of 13 countries had a big meeting in St Petersburg, Russia from November 21 to 24, 2010.The meeting was about tigers. They talked about the ways to protect the animals in their countries. They agreed to spend more money protecting tigers and they wanted to double the number of tigers in the world before 2022.

    Tiger is one of the world's most endangered animals. The World Wildlife Fund （WWF） says, there are only about 100,000 wild tigers now. And the number is becoming smaller and smaller. 'If nothing happens, tigers will face disasters,' said WWF spokeswoman Marie von Zeipel.

Nine types of tigers lived 100 years ago, but now at least three of them have died out. ‘If people leave tigers alone and don't kill them, then the number of tigers will double in 10 years,' said Jean-Christoph Vie, a French tiger expert (专家).

    China is one of the 13 countries where tigers live. There are about 50 wild tigers in China now. They are the Bengal tigers in Tibet, Indochinese tigers in China's southwest, and Siberian tigers in the northeast. The South China tigers lived in southeast China many years ago but disappeared in the 1970s. Many experts think they have already died out.

    Today there are 6 billion people on the earth. By the year 2050 there may be 12.5 billion. There are a lot of people to feed. We need more food.

One way to produce more food is by growing stronger plants. For thousands of years，farmers have made plants better. Every season, they pick the best plants for the next season. It works very slowly. Since 1983, scientists have been able to change plants more quickly by changing their genetic material (遗传物质). Foods from plants grown in this way are called genetically modified foods (转基因食品), or GM foods.

    By changing the genetic material of a plant, it is possible to make new plants. They make plants which are strong against plant diseases. They can also help with our diseases: a kind of rice is being prepared, for example, which stops people from becoming blind.

    Rich countries produce GM foods because they are easy to grow and bring in more money. Poor countries are interested in them because they help produce more food.

    GM plants are not natural. No one knows how good or bad they are. Making GM foods is only one way of feeding people in 2050. There are strong feelings against them, because they are unnatural. They may feed people, and then hurt them or their children later. But, both rich and poor countries are very interested in their use, and they are not going to go away. In 2050, we may think differently about them.

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Recently, China announced it had achieved success in drilling fire ice or methane hydrate (天然气水合物，即可燃冰), from the seabed in the Shenhu area of the South China Sea. It produces high amount of energy when it is burned, leaving nothing but dioxide and water.     Many countries, including the United States and Japan, have long beeaban doing research on methane hydrate, but taking it from bottom of the sea has been a common problem they are facing. According to reports, China succeeded in drilling methane hydrate for a number of days continuously and got an average of over 16,000 m3 daily. It is believed to be a big breakthrough.

Scientists say there is about 21, 000 trillion (万亿) m3 of methane hydrate in the world. If we can use it, it can meet the world's energy need for 1, 000 years. However, it is too early to say a new energy source (来源) has been found because we are still facing two main challenges—environmental risk and economic (经济的)cost. When methane hydrate is taken from the seabed, it may go into the air easily. That's very bad for the environment because methane is one of the worst greenhouse gases. Besides, drilling methane hydrate is very expensive as well.     However, China's technology breakthrough is very important because it shows the way researchers across the world should take. It also raises hopes that one day we can drill methane hydrate as a source of energy.

    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.

    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.