Using too much water or throwing rubbish into our rivers are clear ways that humans can put our water supply in danger , but we also affect our water supply in less obvious ways. You may wonder how paving(铺砌) a road can lead to less useable fresh water. A major part of the water we use every day is groundwater. Groundwater does not come from lakes or rivers. It comes from underground. The more roads and parking lots we pave ，the less water can flow into the ground to become groundwater.

    Human activity is not responsible for all water shortages(短缺). Drier climates are of course more likely to have droughts(干旱) than areas with more rainfall, but in any case, good management can help to make sure there is enough water to meet our basic needs.

    Thinking about the way we use water every day can make a big difference, too In the United States , a family of four can use 1.5 tons of water a day! This shows how much we depend on water to live, but there's a lot we can do to lower the number.

    You can take steps to save water in your home. To start with use the same glass for your drinking water all day. Wash it only once a day. Run your dishwasher (洗碗机)only when it is full 。Help your parents fix any leaks in your home. You can even help to keep our water supply clean by recycling batteries instead of throwing them away.

    CHICAGO(Reuters)－Smoking not only can wrinkle (皱纹) the face and turn it yellow—it can do the same to the whole body, researchers reported on Monday.

    The study, published in the Archives of Dermatology, shows that smoking affects the skin all over the body－even skin protected from the sun.

    "We examined non-facial skin that was protected from the sun, and found that the total number of packs of cigarette smoked per day and the total years a person has smoked were linked with the amount of skin damage a person experienced," Dr. Yolanda, who led the study, said in a statement.

    "In participants older than 65 years, smokers had significantly more wrinkling than nonsmokers. Similar findings were seen in participants aged 45 to 65 years." Yolanda's team added in their report.

    The researchers tested 82 people, smokers and nonsmokers, taking pictures of the inner right arms. They ranged, in age from 22 to 91 and half were smokers. Independent judges decided how wrinkled each person's skin was.

    When skin is exposed to sunlight, especially the face, it becomes coarse(粗糙的), wrinkled and discolored with a pale yellow color, Yolanda's team wrote.

    Several previous studies have found that cigarette smoking led to premature(过早的)skin aging as measured by facial wrinkles, the study said, but little has been done to measure the aging of skin not exposed to light.

    The previous research has found that cigarette smoke, among other things, causes blood vessels(血管)beneath the skin to constrict(紧缩), reducing blood supply to the skin.

    Smoking can also damage the connective tissue(组织)that supports both die skin and the internal organs (器官).

    There were smiling children all the way. Clearly they knew at what time the train passed their homes and they made it their business to stand along the railway, wave to complete strangers and cheer them up as they rushed towards Penang. Often whole families stood outside their homes and waved and smiled as if those on the trains were their favorite relatives. This is the simple village people of Malaysia. I was moved.

    I had always traveled to Malaysia by plane or car, so this was the first time I was on a train. I did not particularly relish the long train journey and had brought along a dozen magazines to read and reread. I looked about the train. There was not one familiar face. I sighed and sat down to read my Economics.

    It was not long before the train was across the Causeway and in Malaysia. Johore Baru was just another city like Singapore, so I was tired of looking at the crowds of people as they hurried past. As we went beyond the city, I watched the straight rows of rubber trees and miles and miles of green. Then the first village came into sight. Immediately I came alive; I decided to wave back.

    From then on my journey became interesting. I threw my magazines into the waste basket and decided to join in Malaysian life. Then everything came alive. The mountains seemed to speak to me. Even the trees were smiling. I stared at everything as if I was looking at it for the first time.

    The day passed fast and I even forgot to have my lunch until I felt hungry. I looked at my watch and was surprised that it was 3:00 pm. Soon the train pulled up at Butterworth. I looked at the people all around me. They all looked beautiful. When my uncle arrived with a smile, I threw my arms around him to give him a warm hug (拥抱). I had never done this before. He seemed surprised and then his weather-beaten face warmed up with a huge smile. We walked arm in arm to his car.

    I looked forward to the return journey.

    Floating on the surface of the seas of the world are billions of tons of small plants and animals called plankton. Most of these plants and animals are too small for the human eye to see. They move about lazily with the currents, providing a basic food for many larger animals. Plankton has been described as the equivalent (相等的东西) of the grasses that grow on dry land, and the comparison is an appropriate one. In potential food value, however, plankton far outweighs that of land grasses. One scientist has estimated that while grasses of the world produce about 49 billion tons of valuable carbohydrates(碳水化合物) each year, the sea's plankton produces more than twice as much.

    Despite its enormous food potential, little effort was made until recently to farm plankton as we farm grasses on land. Now scientists have at last begun to study this possibility, especially as the sea's resources appear even more important as a means of feeding an expanding world population.

    No one yet has seriously suggested that “planktonburgers” may soon become popular around the world. As a possible farmed supplementary food source, however, plankton is gaining considerable interest among scientists.

    One type of plankton that seems to have great harvest possibilities is a tiny creature called krill(磷虾). Growing to two or three inches long, krill are a major food source for the giant blue whale, the largest animal ever to live on the Earth. Realizing that this whale may grow 100 feet and weigh about 150 tons, it is not surprising that each one swallows more than one ton of krill daily.

    Krill swim about just below the surface in huge schools sometimes wide, mainly in the cold Antarctic. Because of their pink color, they often appear as an entire reddish mass when viewed from a ship or from the air. Krill are very high in food value. If krill can feed such huge creatures as whales, many scientists reason, they must certainly be competitors among possible new food sources for humans.

Family Fun in Canadian Museum of Nature

    Bring the whole family to rediscover our fully redecorated museum.

    WHAT TO SEE AND DO

    Check out What's On for all the events, educational activities and HD movies happening during your visit. Care for birds, dive down into the depths at the helm (舵柄) of a research submersible(潜水器) or explore a cave… on the first floor. Don't miss our gallery play areas on the third floor when visiting with kids. By visiting here, your children will learn more about nature. Check out Our Exhibitions which present our special exhibitions and our galleries. Be sure to stop at our Nature Boutique on the second floor for a vast selection of games, books and nature-related souvenirs from 9:30 am until the museum closes for the day.

    HOURS, ADMISSION, SERVICES AND MORE

    The Canadian Museum of Nature provides a host of information, images and videos on our websites about nature, such as http://www.nature.ca/en/family-fun and http://www.expeditionarctic.ca/.The museum also participates in several social networks. Follow us on Facebook, YouTube, Instagram and Twitter.

    Triple Olympic and world sprint(短跑) champion Usain Bolt of Jamaica said on Monday he expects years of fast feats to ease doping doubts in athletics and has no plans to play American football.

    Appearing on ESPN programs and in light-hearted races outside the television sport network's studios, Bolt said he feels he must prove himself to a skeptical sports world in the wake of past doping scandals(诽谤).

    "I have to prove myself to the world that you can run fast without it," Bolt said.

    Bolt cited the speeds he and countryman Asafa Powell and American Tyson Gay have achieved without positive doping tests.

    "We just (have to) continue to run fast," Bolt said. "In a couple of years everyone will continue to watch again and have less doubts."

    Bolt won gold in the 100m, 200 and 4x100 relay in world record times at last year's Beijing Olympics and last month in Berlin set world records of 9.58 seconds in the 100 and 19.19 in the 200 and helped a relay title in a World Championships treble.

    "I want to be a legend in the sport. For me it's all a focus on winning championships after championships," Bolt said.

    "I don't consider myself a legend. When I defend my titles I will consider myself a legend."

    Bolt's defending of World and Olympic gold should be the feature attraction of the 2011 IAAF World Championships in Daegu, South Korea, and the 2012 London Olympics.