We can often read interesting “facts” about space online. However, some of them are wrong. The following are some common myths（荒诞说法）about space.

Myth 1: The sun is yellow.

Many people believe the afternoon sun is yellow. However, the light it gives out is white. The earth’s atmosphere （大气层）makes the sun appear yellow and the sky appear blue. This is called Rayleigh scattering（瑞利散射）. The sky is, in fact, as clear as glass.

Myth 2: The asteroid belt（小行星带）is dangerous.

In many movies, the asteroid belt is often described as a dangerous place. It is crowded with rocks that run into each other. However, these movies are wrong. In fact, all the asteroids together weigh only about four percent of the moon. That’s why scientists are excited when they happen to see even one asteroid crashing （碰撞）into another.

Myth 3: The Great Wall of China is the only man-made building that can be seen from space.

It all depends on where you believe space begins above the earth. From the International Space Station （ISS）, you can see the Great Wall and many other man-made buildings. From the moon, you can’t see any buildings, but you may see some city lights.

Myth 4: The moon is very close to the earth.

Sometimes, the moon looks very close. It seems like you can almost touch it. In fact, the moon is about 385000 kilometers away from the earth. If you take a Boeing 747 and fly to the moon at full speed, the journey will take about 17 days!

【推荐3】Many people know that rubbish is a big problem on planet Earth. What many people don't know is that junk has become a problem in outer space too.

According to BBC News, there are more than 22, 000 pieces of space junk floating around the earth. And these are just the things that we can see from the surface of the earth by telescopes (望远镜). There are also millions of smaller pieces of junk that we can't see.

Objects, like bits of old space rockets or satellites, move around the planet at very high speeds, so fast that even a very small piece can break important satellites or become dangerous to astronauts. If the tiniest piece of junk crashed into a spaceship, it could damage the vehicle (交通工具).

To make things worse, when two objects in space crash, they break into many smaller pieces. For example, when a U. S. satellite hit an old Russian rocket in 2009, it broke into more than 2,000 pieces, increasing the amount of space junk.

To reduce additional space junk, countries have agreed that all new space tools can only stay in space for 25 years at most. Each tool must be built to fall safely into the earth's atmosphere after that time. In the upper parts of the atmosphere, it will burn up.

 Many scientists are also suggesting different ways to clean up space junk. In England scientists are testing a metal net that can be fired into space junk. The net catches the junk and then pulls it into the earth's atmosphere to burn up. The Germans are building robots that can collect pieces of space junk and bring them back to Earth to be safely destroyed.

 "The problem is becoming more challenging because we're sending more objects into space to help people use their mobile phones and computers," says Marco Castronuovo, an Italian space researcher.

 "The time to act is now. The longer we leave the problem, the bigger it will become," he says.

Sometimes English learners have to find out the differences between cultures, like Chinese culture and American culture. Although it is hard to tell which culture is better, we should respect (尊重) both of them. Also, to understand those differences can be helpful.

Because American people’s ideas are different from Chinese, it is necessary to discuss the party culture.

The first difference is about the party places. Chinese people are more interested in having a party at restaurants. The party organizers (组织者) often invite a lot of people to come and have fun, such as birthday party and wedding (婚礼) party. But Americans like to have a party at home. Most of their parties are small, and only friends will come.

The second difference is about the time. Chinese guests always go to the party before the actual time. For example, if organizers tell them the party will start at twelve o’clock, it’s polite (礼貌的) to arrive at the restaurant ten or fifteen minutes earlier. Americans won’t do the same as Chinese. In fact, they always go to the party on time or even later, because they are afraid that the organizers won’t prepare everything well if they go there too early.

All in all, remembering these cultural differences will be important if you are going for a trip to America or other countries in the future.

What would people like to eat on their birthday? The answer would be different in different countries. In many countries, people have birthday cakes with candles. The number of candles is the person’s age. The birthday person must make a wish and blow out the candles. If he or she blows out all the candles in one go, the wish will come true. In the UK, people sometimes put a candy in a birthday cake. The child with candy is lucky.

It is getting popular to have cake on birthdays. In China, many people still eat long noodles for their birthday. They never cut up the noodles because the long noodles are a symbol of long life. In some places, people also eat eggs on their birthday. They are a symbol of life and good luck.

All of these birthday foods may be different, but the ideas are the same. They bring good luck to the birthday person.

【推荐3】The US singer Barbra Streisand loses her pet dog. She loves her dog so much and can’t forget it. So she takes $50,000 out to clone（克隆）her dog. Barbra is not the only one. Now there are a lot of people having the same choice because they want to have their pets again. Any pet keeper can clone their pets when they have about $50,000 or more. But is cloning pets really a good idea?

It’s not easy to clone a pet. It needs the help of a mother pet. First, people take some cells（细胞）from a pet. Then they get some cells from the mother pet. After that, people take the cells of the two pets back to the mother pet. A new pet will come to life 60 days later.

But some scientists don’t think pet cloning is right. They say that if people clone their pets, they will never have new ones. Now lots of dogs and cats are there for a home. Pet cloning is really unnecessary（不必要的）.

It’s true that someone is selling a dream of never having to leave pets. But this is not a healthy dream. The cloned pet looks like the old pet, but it is a new pet. It needs all your love, not part of it, and not from the old dog. So why not just show love to a usual pet?