Chinese students aren't the only ones who have a sleep loss problem. In Australia, teenagers are also missing, on average, one hour's sleep every night during the school week.

    Organized activities and homework push bedtimes later, the first large-scale Australian study of children's sleeping habits has shown. Their sleep deprivation (剥夺) is enough to cause “serious drop-offs in school performance, attention and memory”, and governments should consider later or flexible school start times, said the study's leader, Tim Olds.

    His survey, of more than 4,000 children aged 9 to 18, found those who slept least did not watch more television but spent their time socializing (相处) with family or friends or listening to music.

    “Almost all children get up at 7 or 7:15 — they have to get to school on time,” said Olds. He favors a later start over an earlier finish because he believes organized sports and activities would still consume the latter end of the day.

    Olds' research also establishes lack of sleep as a cause of weight gain in children, and a possible source of future problems with depression, anxiety and increased susceptibility (易感性) to illness.

    It was already known that overweight children sleep less, but Professor Olds found sleep duration(时长) was strongly linked to weight across the full range of body sizes. The thinnest children sleep 20 minutes more than the obese. This showed being overweight had no specific effect on sleep patterns, and it was more likely that shorter sleep times stimulate (刺激) appetite and make kids hungry.

    The US National Sleep Foundation says teenagers aged 13 to 18 need eight to nine hours' sleep a night. Younger school-aged kids need 9 to 11 hours.

    On that basis, Professor Olds said, half of Australian children are under-sleeping on weekdays and a quarter on weekends.

    Wedding is one of the most universal traditions in the world. But it's celebrated differently by people around the world. Now let's know something about these traditions.

       In Jamaica, weddings are a community affair, with the whole village often coming together to help plan the big day. People in the village gather in the street to see the bride and if she isn't in perfect shape, she will be publicly criticized. And while women wear the typical white wedding dress，men wear a bush jacket for the event. Several cakes are baked for the ceremony and on the wedding day married women wearing white dresses carry the confections (甜点) to the wedding. The reception is often held at the groom's house, in a booth specially built for the event. The wedding celebration also includes a lot of dancing.

    In Welsh wedding tradition, a man carves a spoon out of wood and gives it to the woman he loves. H she wears it, they are engaged (订婚）. Brides are often hidden by their families just before their wedding day. The groom and his family follow and whoever finds her will be the next to get married.

    In her bouquet, a Welsh bride carries a small tree with shiny green leaves and white flowers that smell nice as a symbol of love, and gives a cutting of the plant to her bridesmaids as well. If the bridesmaid plants the cutting in her yard and it blooms, she will soon marry, according to Welsh tradition.

    In Czechoslovak, before the wedding, the bride's friends traditionally plant a tree in her yard and decorate it with colored ribbons and eggshells, because, according to the legend, the bride will live as long as the tree. Before the marriage vows, a baby is placed in the couple*8 bed to bless their fertility. During the wading ceremony, Czech women surround the bride*, dancing and singing. They then remove her veil (面纱）and make her put on a handrnade babushka ( a woman's head scarf).

Most young people enjoy some form of physical activity. It may be walking, cycling or swimming, or winter, skating or skiing. It may be a game of some form—football, hockey, golf or tennis. It may be mountaineering.

    Those who have a passion for climbing high and difficult mountains are often looked upon with surprise. Why are men and women willing to suffer cold and hardship, and to take risks on high mountains? This astonishment is caused, probably, by the difference between mountaineering and other forms of activity to which men give their leisure.

    Mountaineering is a sport and not a game. There are no man-made rules, as others, as there are for such games as golf and football. There are, of course, rules of a different kinds which would be dangerous to ignore, but it is this freedom from man-made rules that makes mountaineering attractive to many people. Those who climb mountains are free to use their own methods.

    If we compare mountaineering with other more familiar sports, we might think that one big difference is that mountaineering is not a “team game”. We should be mistaken in this. There are, it is true, no “matches” between “teams” of climbers, but when climbers are on a rock face linked by a rope on which their lives may depend, there is obviously teamwork.

    The mountain climber knows that he may have to fight forces that are stronger and more powerful than man. He has to fight the forces of nature. His sport requires high mental and physical qualities.

    A mountain climber continues to improve in skill year after year. A skier is probably past his best by the age of thirty. But it is not unusual for men of fifty or sixty to climb the highest mountains in the Alps. They may take more time than younger men, but they perhaps climb with more skill and less waste of efforts, and they certainly experience equal enjoyment.

    US inventor Thomas Alva Edison once said: "Genius is one percent inspiration and 99 percent perspiration." He was not exaggerating. Perspiration, indeed, plays a very important role in Chinese scientist Tu Youyou's success.

    Tu was given the Nobel Prize in Physio logy or Medicine in 2015 for discovering a new drug for malaria, a deadly disease caused by the bite of some types of mosquito. She is the first Chinese citizen to win a Nobel Prize in science. "It is the pride of the whole Chinese science community, which will inspire more Chinese scientists," China Daily noted.

    Malaria is a disease that infects around 200 million people and k ills about half a million people each year, according to the Economist. Tu's discovery has saved millions of lives, especially in the developing world. According to the World Health Organization, by 2013 malaria deaths had fallen by 47 percent compared with 2000.

    But the road to this achievement was a tough one to travel. In the late 1960s, during the "cultural revolution" (1966-1976), Tu joined a government project on which she began research on a new malaria drug.

    In the beginning, Tu read a lot of old folk remedies(药方), searched texts that w ere hundreds or thousands of years old and traveled to remote places.

    Over several months, Tu and her team collected over 600 plants and created a list of almost 380 possible remedies.

    "This w as the most challenging stage of the project," Tu told The Beijing News. "It was a very labor-demanding and dull job, in particular when you faced one failure after another."

    But the hard work and the dullness failed to break the team's spirit. In the following months, she and her team tested the remedies on malaria- infected mice and they found that an extract(提取物)from the plant qinghao seemed to work w ell.

    Not that the work was easier after that. The fact that the extract didn't always work against malaria discouraged some of her teammates. But Tu was ambitious to make a contribution to the world and so she encouraged her teammates to keep going. They decided to start again from the beginning.

    In 1971, they were rewarded for their efforts. After nearly 200 failures, Tu finally made an extract that was 100 percent effective  against malaria parasites.The extract was called "Artemisin in"(青蒿素).

    Thanks to decades of hard work, Tu and her team had "provided humankind with powerful new means to combat these diseases that affect hundreds of millions of people every year," said the Nobel Prize Committee. "It has greatly improved human health and reduced suffering."

Lovers often use flowers, chocolates, sweet gifts or grand declarations to express feelings deep in their hearts. But this year, you could let your love take off by traveling with that special someone on a romantic adventure. These are some romantic destinations which might bring new joy to your life and, most importantly, more fun and excitement to your relationship.

Stairs of the Turks, Sicily

Scala dei Turchi, or Stairs of the Turks, at Realmonte, southern Sicily, Italy. The Scala is formed by mud, a sedimentary rock(沉积岩) with a characteristic white color and is a popular tourist attraction and place to sun bath. In the film Malèna, the hero, 12-year-old Renato, always stare at the sunset here with his friends.

Somerset House in London

Located in central London, Somerset House is a popular filming location with its exterior featuring in several big budget Hollywood films. In the winter, its central courtyard is turned into an open-air playground for skating, as seen during the well-received film Love Actually.

Pokhara, Nepal

Pokhara is considered the tourism capital of Nepal. With two major hilltops as viewpoints to see the city and surrounding view, the city has recently added a bungee jumping site (the second in Nepal): Water Touch Bungee Jumping. Visitors also come here for adventure activities such as paragliding and skydiving. In the film Up in the Wind starring Ni Ni and Jing Boran, two young people climb up to the mountaintop and wait for the strong wind to carry them for paragliding. It becomes a moment of spiritual uplift.

Otaru, Hokkaido, Japan

A canal decorated with Victorian-style street lamps runs through Otaru. The city attracts many Japanese tourists as well as Russian visitors. Otaru is well known for its beer, fresh sushi and handicrafts like studio glass and musical boxes. At the poster of Japanese film Love Letter, Hiroko Watanabe stands among the snowy town and honors her dead lover.