Are you able to send a letter with pictures and sounds to someone somewhere in the world without a stamp(邮票) on it? Using a computer you can send e-mails quickly and easily. The post is much slower than e-mail. E-mail can send its message to the other side of the world in seconds.

    E-mail is easy to use and it saves time and money. The differences in time in different parts of the world do not matter when sending e-mail. It's twenty-four-hour service(服务) that you can send e-mail at any time of the day or night. No one has to be there to get e-mail. It does not matter if your friends are in beds when you send e-mail to them, or you are seeing a movie at the movie theater when they send e-mail back.

    As space science develops, man has learnt more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger as well as success.

    Scientists have found out that the radiation is the greatest danger to spacemen in space. When spacemen are working in space, they are in danger of the radiation from the Sun and other stars, which is bad for their health.

    Space rubbish is also a great danger to spacemen. It's reported that there were 9,000 man-made things flying in space. About 30% of these are satellites, 10% are spaceships, and the rest space rubbish. A small piece of these can knock a spaceship window and cause some damage.

    Scientists are watching and reporting any possible danger all the time. They are working to deal with space rubbish. Although space is really dangerous, it interests many people on Earth. In the near future, it may become possible for people to spend a few days in a space hotel. We may even choose to leave the Earth and live in space in a few years. So we should do something to help improve the space environment.

    We know people can be nice, but what about animals?

    Scientists say that some animals are capable(有能力的)of being nice. Animals that live in groups-like foxes, chimpanzees(大猩猩), and elephants-follow rules. They have to follow rules to get along and to survive(生存). However, animals can act nicely, even when they don't have to. Here are some surprising stories about animal behavior.

    Most people usually walk away when someone is unkind to them. Marc Bekoff, a researcher at the University of Colorado, saw a female(母的)red fox do just that. The female fox was unhappy because a male(公的)fox played roughly(粗鲁地)with her. When she walked away, the male fox showed her that he wanted to play nicely. He lowered his head and rolled on his back. The female fox gave him another chance, and this time, he played more gently.

    Geza Teleki is a scientist who studies chimpanzees in Tanzania. One day, Teleki hiked far away from his campsite. He didn't have any food. Teleki wanted some fruit from a tree, but the tree was too tall. A young chimpanzee watched him curiously as he tried to get something to eat. The chimpanzee climbed the tree, picked the fruit, and gave it to him!

    An elephant in Kenya hurt his trunk(象鼻子). He needed help because he couldn't put food into his mouth. Researcher Kayhan Ostovar watched silently. He saw the hurt elephant show his sore trunk to a healthy elephant. The healthy elephant didn't need any more information. He took a bush and put it carefully into his new friend's mouth.

    Hippos(河马)and crocodiles are usually good friends. They hang out together in rivers. But Karen Paolillo, a wildlife expert in Zimbabwe, saw something surprising. One day, a crocodile tried to eat a monkey that was next to a river. A hippo ran quickly to the crocodile and chased it away. Why did the hippo attack(攻击)the crocodile? Paolillo says hippos sometimes protect other animals from crocodiles.

    Is there intelligent (有智力的) life on other planets? For years, scientists said "no" or "we don't know". But today this is changing. Seth Shostak and Alexandra Barnett are astronomers (天文学家). They believe intelligent life exists (存在) somewhere in the universe. They also think we will soon contact these beings (人；生物).

    Why do Shostak and Barnett think intelligent life exists on other planets? The first reason is time. Scientists believe the universe is about 12 billion years old. "This is long enough for other planets to have intelligent life," say Shostak and Barnett. The second reason is size—the universe is huge. "Tools like the Hubble Telescope (哈勃望远镜) have shown that there are at least 100 billion galaxies," says Shostak. "And our galaxy, the Milky Way, has at least 100 billion stars. Some planets going around these stars might be similar to Earth."

    In the past, it was hard to look for signs of intelligent life in the universe. But now, powerful telescopes (高倍望远镜) allow scientists to discover smaller planets. These planets might have intelligent life.

    Have beings from space already visited Earth? "Probably not," says Shostak. However, intelligent beings may contact us in other way, such as radio signals (信号). In fact, they may be trying to communicate with us now, but we don't have the right tools to receive their messages. However, this is changing. By 2025, we could make contact with other life forms in our universe and we might help each other.

The traditional Chinese lunar calendar divides the year into 24 solar terms (节气). It starts from the beginning of Spring and ends with the Greater Cold, moving in cycles. It is still useful today to guide people's lives through special foods, cultural ceremonies and even healthy living tips.

Grain Buds (小满), the 8th solar term of a year, begins on May 21 this year, and ends on June 4. It means that the seeds (种子) from the grain are becoming full. During the Grain Buds, summer harvest is  about to begin. A saying about rain during this time mentions, "Heavy rainfall makes  the river  full." Because of the great increase (增长) in rainfall, rivers are full of water. This is a good time to enjoy fish. It  is also a harvest season for fishermen.

Frost's Descent (霜降), the 18th solar term of the year, is the last solar term of autumn. The weather becomes much colder than before and frost begins. The apple is one kind of recommended (推荐的) fruit during Frost's Descent. There are many sayings about apples ' benefits (益处) in China, such as "Eat an apple after meals. Even old men can be as strong as young men."

Minor Cold (小寒) is the 23rd one. For most areas of China, it marks the start of the coldest days of the year and people always start preparing for the Lunar New Year. According to traditional Chinese medicine thoughts, people need to eat food that has more yang (阳) energy to prevent cold from harming their bodies. Another important traditional food for Minor Cold is Laba porridge (腊八粥).

 Have you ever tried to see the world from a"one-meter height"? Building child-friendly cities will offer some {#blank#}1{#/blank#}(机会). They make better places for children in services, rights, and play areas.

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