Dear humans,

It's the first time I write to you, my Children. I sent you many messages in the past, but you didn't take them seriously. So I decide to write you a letter.

First, let me tell you more about our family. Dear humans, besides you, I have many other children. Some of them fly in the sky; some of them swim in the water; some live in ice-covered places; some run in the grasslands.

They might be very close to you, or even live in your house. But there are others that you may never have the chance to meet.

You bring them home to be your pets, friends and helpers. You put them in the zoos. You kill them for their meat and fur. And you even hunt them for fun. They bring you money and happiness, but they also bring you illness and death.

I hope you remember that wild animals are not your food, clothes or furniture. They are not killers, either. They are, in fact, your brothers and sisters. You should grow up together. I'm worried that one day you will be lonely if you keep killing them.

So, grow up, humans. Grow up to be more loving and caring. I hope you and all the wildlife can live happily in my arms.

Yours,

Mother Earth

Many people take running as a way to keep fit. They like to run in hot weather and enjoy the feeling of being wet through with sweat (汗) while running. Cold weather during winter months, with low temperatures and freezing cold winds, may keep people from running in the open air.

However, a new study shows that the drop in temperature is a good reason to run. In fact, running in cold weather helps improve one's performance. Many runners might find it easier to run in winter than in hot weather. The body needs less water on a cold day than in warm weather. In addition, lower temperatures reduce stress on the body. When you run in cold weather, your heart rate is lower.

John Brewer is a professor of applied sports science at St. Mary's University in London. For this study, he and other researchers put a group of people into a room where summer and winter weather conditions are recreated. The test subjects were asked to run 10,000 meters under both conditions and their biological measurements were recorded and studied.From the study, every movement runners make produces heat. The heat can be really damaging unless the body can lose it. One way in which people lose heat is by sweating. The body loses heat through sweat. The body also loses it by transporting the blood to the surface of the skin and it puts more stress on the heart, especially in hot conditions because it's much harder to lose heat when the outside environment is warm. As the result shows, running in hot temperatures results in 6 percent higher heat rates.

When running in cold conditions, the body does not have to work hard to move blood to the skin surface. Therefore, it requires less energy. The most important thing for people who run in cold conditions is to wear the right clothing. Keep as dry as possible when exercising in low temperatures. Wear warm and light clothing to keep sweat away from your skin. So don't let winter weather keep you indoors. Simply get ready for the low temperatures and start running.

Do you know what an e—friend is? You make a friend with him or her by sending e—mails. Having e—friends is good for you. You can tell them your family, problems and good things. They can teach you many things and help you get out of problems. Some of them may send you e—cards on your birthday.

If your e—friends come from English—speaking countries, they will help you learn English. Writing to them in English is good for your English learning. Some of them may invite you to their countries, and take you to visit their countries.

Where can you make e—friends? You can visit some websites. There are many boys and girls, and you can make friends with some of them.