Have you ever dreamed about sending a letter to yourself or your friends in the future? While express mail(快递) is a fast way to send your letters, there is another type of mail appearing in China as a new business—future mail.

     “The letter should be sent next Mother's Day and not a day earlier!” Lin Xiaofan, acollege student in Shanghai, tells one of the companies offering the service.

Lin Xiao fan wrote the letter to her mother nearly a year earlier to express her love to hermother for next Mother's Day.

“Offering thisservice makes people slow down and lets them understand the meaning of ‘time'in another way,” said Zheng Zhimin, manager at a “future mail” company. Zheng thinks “future mail” letters help remind us of care, friendship and love.

      While “futuremail” is becoming more and more popular, some people are wondering what will happen if the postal address changes or if the company goes broken before theletters arrive.

     Zheng said customers are glad to sign a contract(签订合同) to make sure that they canbe compensated if their letters are lost or damaged.

    Most of the customers are college students and young white-collar(白领) workers. Psychologists (心理学家) said that young Chinese might have a new way to express their feelings through this service. Most peopleput their hopes and wishes in the letter so that they can experience the connection(联系) between the past and the present when they receive theletter.

Suggestions for Traveling

    Sitting too much is now listed with smoking and junk food as a bad habit that increases your risk of heart disease.

    New Australian research shows that half-an-hour in the gym will not make up for the waist-expanding damage caused by spending the rest of the day sitting.

    But the good news is that doing chores(家务杂事) in the house or gently walking around the office while on the phone might be enough to keep you fit.

    The study joins the growing body of evidence suggesting too much sitting might undo the benefits of exercise.

    The study measured the intensity(强度)of physical activities in 168 subjects over seven days. If found that, regardless of how much exercise they did or their total sitting time, those who took more breaks from sitting had lower risk of thick waists and lower levels of blood lipids(脂质).

    “Higher levels of blood lipids have been linked to a heightened risk of heart disease,”principal researcher Genevieve Healy of the University of Queensland said. "What the study shows is that there are benefits in just getting up regularly and interrupting your sitting time."

    Researchers behind the Stand up Australia project have written to the Rudd Government requesting $ 3.5 million for a two year study into how long sitting affects the health and productivity of workers.

    The latest study builds on work that is shifting the health promotion focus from purposeful exercise, such as running, to lower intensity activities throughout the day.

    The Australian research bas been backed up US studies, which show standing up is enough to double the metabolic(新陈代谢) rate and the amount of calories burnt.

    “To hold a body that weighs 77kilograms upright take a .fair amount of energy from muscles", said professor Marc Hamilton from the University of Missouri. "There is a large amount of energy associated with standing every day that cannot be easily replaced by, 30 to 60minutes in the gym."

    Sun bears(马来熊)are the smallest of the world's eight bears species(物种). They have a black coat and a white or golden colour on their bodies. Their homes are in the tropical(热带雨林)of Southeast Asia. They live in trees and eat both plants and animals. They can grow to be 1.4 metres in height and 65 kilograms in weight. They usually live alone and are happy to spend most of their time by themselves.

    Scientists studied sun bears in the Bornean Sun Bear Conservation Center. They found that although sun bears live alone, they have developed a surprising social skill. They can copy (模仿) other sun bear's facial expression (面部表情) as a form of communication. They can even copy exact muscular (肌肉的) movements that other sun bears make— such as making a face.

    The ability to copy facial expressions is found in humans, gorilla's (大猩猩), some monkeys and some other animals. But until now, only humans and gorillas have the ability to exactly copy facial expressions. However, scientists found that sun bears can copy facial expression as well as humans and gorillas. This surprised them because sun bears are alone and they have no close relationship with human beings.

    Although they live alone in the wild, the sun bears in the study often played gently with each other. Sometimes they played with faster actions as hitting and biting. Scientists are still not sure what messages the sun bears were sending to one another.

    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.