帖子列表

• What Is the Colour of Sunlight?

  readme 发表于: 2008-02-26,

  　　Why does the sun look red at sun-rise and sunset？ When the sun rises and sets， it goes through a very thick layer of air and a lot of sun-light is absorbed by.

• Why Does the Sunny Sky Look Blue?

  readme 发表于: 2008-02-26,

  　　In the sky there is a very thick layer of air which is colourless. So why does the sky look blue？ It has something to do with the irradiation of sunlight. .

• Is the Sun a Big Fire Ball?

  readme 发表于: 2008-02-26,

  　　Although the sun is over one million kilometres away from us， we still feel its heat. In this sense， we can say that the sun is a very big fire ball. 　　The.

• Can the Sun Bum Out?

  readme 发表于: 2008-02-26,

  　　The sun brings us light and warmth. But what can we do if the sun burns out？ 　　There is no need to worry. 　　The sun is like a big stove using atom ener.

• How Can the San Be Covered by Clouds Sin.

  readme 发表于: 2008-02-26,

  　　Our hands are small. But if you put one hand over your eyes， you won't be able to see the sky. When we look at things， those near us always appear bigger than.

• Why Can't We See the Sun at Night?

  readme 发表于: 2008-02-26,

  　　During the day time we can see the sun， but we cannot see it after sunset. Why is that？ The earth revolves all the time. During the day the earth faces the su.

• Which Is Bigger, the Sun or the Moon?

  readme 发表于: 2008-02-26,

  　　The sun appears to be as big as the moon. A dually， the sun is 100 million times bigger than the moon. So why does the sun look just as big as the moon？ This .

• Which Is Bigger, a Star or the Moon?

  readme 发表于: 2008-02-26,

  　　Let's do a simple test first. Take a big balloon and a small apple and put them together. Which is bigger？ The balloon， of course. Now， put the apple in front .

• Why Does the Moon Always Follow You Wher.

  readme 发表于: 2008-02-26,

  　　When you travel by train and look out the window， you'll feel the lamp posts and houses all run backwards. But when you look carefully， you'll find the object.

• What Is on the Moon？

  readme 发表于: 2008-02-26,

  　　Like the earth， there are mountains， valleys and flat land on the moon. However， on the moon there are no trees in the mountain， there is no water in the valley.

• Why Is the Moon Sometimes Round and Some.

  readme 发表于: 2008-02-26,

  　　The moon， like the earth， is round all the time. Why then does the moon we see everyday change its shape？ The moon does not shine by itself. It is the sun-ligh.

• Why Do the Stars Shine in the Sky

  readme 发表于: 2008-02-26,

  　　When the stars shine in the evening sky， they are like many lights in the sky. How do the stars shine？ As we have already learned the sun is bright and hot li.

• Why Do the Stars Twinkle in the Sky

  readme 发表于: 2008-02-26,

  　　At night sometimes the stars twinkle like people blinking their eyes. Actually， it is the air playing a trick. The earth we live on is surrounded by a thick .

• Why Can't We See the Stars During the Da.

  readme 发表于: 2008-02-26,

  　　When you turn the light off at night， the room becomes very dark. When you light a candle in the dark room， it seems very bright. But if you turn on the light.

• Why Starry Night Always Followed Sunny D.

  readme 发表于: 2008-02-26,

  　　Sometimes there are more stars in the sky than others. This has a lot to do with the cloud in the sky. If the cloud is thick， it will cover the star light an.

• Are All the Stars White

  readme 发表于: 2008-02-26,

  　　Besides white stars， there are also yellow， red and blue ones. The colour of the star is decided by its temperature. When we put a piece of iron over a fire， i.

• What Is the Milky Way？

  readme 发表于: 2008-02-26,

  　　In the clear sky in summer and autumn， we can see， besides other stars， a silvery belt that looks like a river. People call it the Milky Way. This is formed by.

• Are There More Stars in Summer Than Wint.

  readme 发表于: 2008-02-26,

  　　There are more stars in some parts of the sky than in others. The place that has the most stars is known as the Milky Way， or the Galaxy. From different posi.

• Are All the Stars the Same Size

  readme 发表于: 2008-02-26,

  　　There are many， kinds of stars. Some are big and some are small. 　　There arc nine planets revolving around the sun. The earth is， one of them. Of the nine .

• How Far Are the Stars from Us

  readme 发表于: 2008-02-26,

  　　The moon is the closest star to the earth. It is over 380，000 kilometres from us. 　　It takes 100 days for us to get there by train or 16 days by airplane..