Mark and his brother Jason both were looking at the shining new computer enviously. Jason was determined not to go against their father's wishes but Mark was more adventurous than his brother. He loves experimenting and his aim was to become a scientist like his father.

     “Dad will be really mad if he finds out you've been playing with his new computer” Jason said, “He told us not  to touch it.”

     “He won't find out,” Mark said, “I'll just have a quick look and shut it down.”

    Mark had been scolded before for touching his father's equipment. But his curiosity was difficult to control and this new computer really puzzled him.

It was a strange-looking machine — one his dad had brought home from the laboratory where he worked. “It's an experimental model,” his father had explained, so don't touch it under any circumstances.” But his father's warning only served to make Mark more curious. Without any further thought, Mark turned on the power switch. The computer burst into life and seconds later, the screen turned into colours, shifting and changing, and then two big white words appeared in the centre of the screen: “SPACE TRANSPORTER.”

     “Yes!” Mark cried excitedly, “It's a computer game. I knew it! Dad's only been pretending to work. He's really been playing games instead!” A new message appeared on the screen:

“ENTER NAMES

VOYAGE 1

VOYAGE 2

    Mark's finger flew across the keyboard as he typed in both of their names.

“INPUT ACCEPTED.

START TRANSPORT PROGRAM.

AUTO-RETRIEVE INITIATED( 自动回收程序已启动).”

    The screen turn even brighter and a noise suddenly rose in volume.

     “I think we'd better shut it off, Mark,” Jason yelled out in terror, reaching for the power switch. A beam(光束) of dazzling white light burst out of the computer screen, wrapping the boys in its glow(光芒)，until they themselves seemed to be glowing. Then it died down just as suddenly as it had burst into life. And the boys were no longer there. On the screen, the letters changed：

“TRANSPORT SUCCESSFUL．

DESTINATION:  MARS.

RETRIEVE DATE:  2025

    According to sociologists(社会学家), every modern industrial society has some form of social stratification(阶层). Class, power and status are important in deciding people's rank in society.

    Class means a person's economic position in society. A commonly used classification is lower class, middle class and upper class. While sociologists disagree on how these terms should be exactly defined, they do describe societies like the United States quite well. One study shows that 53% of Americans belong to the lower class, 46% the middle class, and 1% the upper class. Interestingly, a surgeon earning $500,000 a year and a bus driver earning $50,000 a year both regard themselves as the middle class!

    Power refers to the amount of control a person has over other people. Obviously, people in positions of great power (such as governors) exercise(行使)big power, but people who take orders from others have less power. Power and class do not always go hand in hand, however. For example, the governor of a state has great power, but he or she may not belong to a corresponding (相应的)economic class. Generally, however, there is a relationship between power and class. To our knowledge, there aren't too many people who aren't millionaires in the U．S. Senate!

    Status is the honor or respect attached to a person's position in society. It can also be affected by power and class, but not necessarily so. For example, a university professor may have a high status but not belong to a high social class or have a lot of power over others.

    As Canadians we may have a love-hate relationship with snow.We love the opportunities it provides: skiing,snow-boarding,cross-country and snowshoeing（雪鞋健行）.There are the advantages of creating snowmen.The beauty of the snow seems to blanket our community after a fresh snow.However,you may hear  icy roads,getting stuck in snow banks,temperature dropping;roofs collapsing（倒塌）from the weight of snow go in the hate category.

    To find joy with winter I have tried various activities to get me out and playing in it.My new favorite for the past 10 years is snowshoeing.The sport becomes popular because it only requires you to lift your knees up higher, which provides a greater exercise benefit.

    According to the Canadian Icons website,snowshoes have been a common form of transport in this country for hundreds of years thanks to the creativity of the native people.The oldest snowshoes were made by the Ojibwa people.With the snowshoes our deep snow walking would be possible.The snowshoes allowed them to float on top of the deep snow by having the weight of the walker distributed across the surface.The snowshoes allowed people to go across the top of the globe from Central Asia to Canada.

    This past New Year's Eve day my oldest son and I went snowshoeing as a great way to end the year by getting to the mountain top.We enjoyed a snack at the top and our dog Indiana rounded out our party.My son took several photos along the way of the amazing views to send them to his new city friends.We are fortunate to live in such a beautiful part of this amazing country.

    Snowshoeing is a great activity to combine your exercise with visiting with friends and families.Wear layers, bring water and snacks and go play in the snow.And your friends will share his enthusiastic story with you.

    4-Day Classic Beijing Tour The 4-day classic Beijing tour is designed for tourists who come to visit China for the first time. It covers the most popular and typical places in Beijing, fully displaying the scenery, culture, history, local lifestyles and features, food and drinks, business, etc. for you.

    Day 1：Arrival in Beijing

    Your guide meets you at Capital Airport, and helps you check in at your hotel.

    Enjoy Beijing Duck as welcome dinner.

    Accommodation：Beijing downtown

    Day 2：The Great Wall & the Summer Palace

    Start your day at the most famous part of the Great Wall, the Badaling Great Wall. Leave the downtown for the Great Wall at 8am. Since it is a long drive to the Great Wall （about 2 hours' riding） have a break at the Jade Museum on the way. Lunch will be enjoyed in a local restaurant. In the early afternoon come back to the city and have a sightseeing tour of the Summer Palace.

    Recommended Activity：Beijing Opera Show （Liyuan Theatre, 19：30-21：10 every evening）

    Accommodation：Beijing downtown

    Day 3：Beijing city sightseeing & Local experience

    Your guide meets you at the hotel at 8 am and set out for the day's touring：    Tian'anmen Square and the Forbidden City.

    After visiting the two sites, have a break and get ready for lunch.

    Hutong visit：see some traditional arts of the old Beijing, such as paper cutting and kite making, and visit a local family.

    Accommodation：Beijing downtown

    Day 4：Beijing Olympic sites

    Visit the Olympic sites：Bird's Nest, Water Cube and Olympic Park, witnessing the fast developing modern China. Enjoy some free time after visiting the sites.

    After lunch, it is shopping time and then the tour is over.

    A new study has found that social media could be affecting the sleep of young adults.

    The study is a project of researchers at the University of Pittsburgh's School of Medicine. They found that young people who often use social media are more likely to suffer from sleep disorders than those who use social media less. The researchers say doctors should ask young adults about their use of social media when treating sleep issues.

    "This is one of the first pieces of evidence that social media use really can influence your sleep." said Jessica C Levenson. She was the lead author of a report on the study.

    The researchers set out to examine the connection between social media use and sleep among young adults. Levenson noted that these young adults are possibly the first "generation to grow up with social media."

    The researchers wanted to find out how often young people used social media sites like Facebook, Twitter, Credit and Tumbler. For the study, they gave questionnaires to nearly 1,800 adults, aged 19 to 32. On average, members of the study group used social media sites one hour a day. They also "visited various social media 30 times per week."

    Thirty percent of the study's participants reported having serious problems with sleeping. Those people who used social media a lot were three times more likely to have a sleep disorder. And those who spent the most time on social media were two times as likely to suffer from sleep disturbances.

    Levenson said the number of times a person visits social media is a better predictor of sleep problems than overall time spent on social media. If this is true, she adds, then practices that stop such behaviors may be the most effective.

Biofuels (生物燃料), gained from plants and animal matter, are a key solution to the environmental problems caused by fuels like coal. "Bioalcohol (生物酒精) is the most common biofuel and is produced by sugars found in materials such as corn. With some engine redesigned, it can be used directly by cars, buses, etc. ," says Professor Daniel Tan, "12 percent of transport fuel could come from biofuels, especially bioalcohol, by 2030. "

But a 2016 study of biofuels said, "Bioalcohol presently is mostly produced with food crops. Altogether, the environmentally-friendly biofuels rely on about 2-3 percent of the global water and land used for agriculture, which could feed a large number of hungry people. "

Energy experts have therefore been trying to deal with the problem. Recent research led by an international team found that the agave (龙舌兰) plant might offer a way out. This plant tends to be the right bioalcohol source to supersede others such as sugarcane (甘蔗) and corn.

Daniel Tan explains that the agave can be grown in unfavorable conditions and is not a major food crop. "It can grow in areas that lack water and rainfall without being watered by farmers, and it does not compete with food crops or put demands on limited water. This kind of useful plant is recently being grown in Australia. It can survive Australia's hot summers," he says.

The study finds that sugarcane produces just a little more fuel per square meter each year than the agave. However, the agave outperforms sugarcane in a range of areas, including pollution to the earth, and water using. The agave uses 69 percent less water than sugarcane and 46 percent less water than corn for the same amount of fuel produced. As for corn，it produces less fuel per square meter each year than the agave.

However, Daniel Tan states: "The first generation of bioalcohol from the agave recently faces a big competition from oil, whose recent low price makes it far more attractive to customers. Without some policy support from the government, bioalcohol production from the agave faces big challenges. "