In the past， many students practiced English with their pen friends — they sent letters to people all around the world. However， we now send emails to others and chat with people who live quite far away on the Internet.

    Here's some advice on how to succeed in your online language exchanges：

    How to start a conversation when speaking English online When you speak to somebody online， start by asking “Yes or No” questions. Use questions such as “Do you like …?” or “Can you …?” or “Have you ever …?”

    Remember your goal. You are trying to learn about the other person. Think about things you enjoy and try to find some common ground between you. And share your own experiences to show that you have similar interests. If you only ask questions， you will sound like a policeman or a policewoman!

    How to keep a conversation going “Listen” carefully. In that way， you can get to know somebody well. When you know him or her well， you will have more to talk about.

    Then ask follow-up questions. After you “listen”， use what you “hear” to learn more about that person. Use “open ended” questions， such as “What do you think of …?” or “What was the most interesting experience ...?”

    Remember some basic rules for online language exchanges.

    Be patient. Do not try to find a good friend right away.

    Be careful. Don't give any personal information on the Internet， especially your address， telephone number， and even your real name.

    Rainforests (热带雨林) cover six percent of the earth's surface (表面). There are rainforests in many parts of the world. About 75 percent of animals live in rainforests. There are many beautiful birds, insects and so on. Some of them live on the ground, some live under the ground and others live in the trees, over 30 meters from the ground. It is always hot in the rainforests and the ground is always wet. It is also very dark there.

    The rainforests are very important for us. We need them! The trees and other plants in the forest help to make the air clean. They also help to control (控制) the temperature.

    Unfortunately, in many places, the rainforests are in danger. For example, many years ago there was a large rainforest in Java, but now there is nothing. The same thing happens now in many other parts of the world. It's time to take action to save the rainforests. We can never imagine a world without rainforests. If rainforests disappeared from the earth, we wouldn't find any trees, flowers or fruits. What's more, we wouldn't get clean air, and we wouldn't find any animals. The worst result would be that we wouldn't find any humans.

    There is a lot of salt on the Earth, and it mixes very well with water.

There is some salt in all water. Water on the land runs into lakes and rivers. These rivers run into the seas and oceans. They carry a little salt with them. Some of the ocean water moves into the air and clouds. It evaporates. Salt cannot evaporate. It stays in the oceans.

    The water in the oceans has more salt than river water. There is about 3. 5% salt in the ocean water. Some seas have more salt than others.

    Some of the water leaves the lakes. It evaporates, but the salt cannot. These lakes are very salty. There are two famous lakes like this. They are the Dead Sea in the Middle East and the Great Salt Lake in Utah(犹他州）in the United States. They are much saltier than the Atlantic Ocean（大西洋）and the Pacific Ocean(太平洋）.

    Dolphins are not fish, but warm-blooded animals. They live in groups, and speak to each other in their own language. In this they are like other animals, such as bees and birds. But dolphins are very different from almost all land animals. Their brain is nearly the same size as our own, and they live a long time—at least twenty or thirty year.

    Like some other animals, dolphins use sound to help them find their way around. They also make these sounds to talk to each other and to help them find food. We now know they do not use their ears to receive these sounds, but the lower part of the mouth, called the jaw.

    Strangely, dolphins seem to like man, and for thousands of years there have been stories about the dolphin and its friendship with people.

    There is a story about sailors in the 19^th century. In a dangerous part of the sea off the coast of New Zealand, they learnt to look for a dolphin called Jack. From 1871 to 1903 Jack met every boat in the area and showed it the way. Then in 1903 a passenger on a boat called The Penguin shot and wounded (伤害) Jack. He recovered and for nine years more continued to guide all ships through the area—except for The Penguin.

    Today, some people continue to kill dolphins, but many countries of the world now protect them and in these places it is against the law to kill them.

    Americans were shocked to discover that the national bird was in danger of disappearing from the skies forever. Studies in 1970 showed only about 1,000, or fewer, bald eagles(秃鹰) in the country.

    The major cause of the problem was people. The spread of civilization(文明) destroyed many of the eagles' feeding and nesting areas. And the eagles were being affected by D-D-T and other insect poisons. The poisons were in the animals the eagles ate. They reduced the eagles' ability(能力) to use calcium(钙). This made the outside of the eagles' eggs very thin. Often, the eggs broke before baby birds were developed.

    In 1972, the U. S. government banned(禁止) D-D-T. People also became interested in protecting places where eagles live. And stronger efforts were made to carry out laws protecting the birds. Scientists began a program that placed baby bald eagles which were born under human care, into nests of wild bald eagles. Often, the wild birds accepted the babies.

    These efforts appear to have been successful in saving the American bald eagles. Today the number of the bald eagles has increased to more than 11, 000.