Climbers at Qomolangma are being asked to clean up after themselves.

Qomolangma has earned the nickname（绰号）the Worldˈs Highest Garbage Dump（垃圾场）.

Climbing Qomolangma,the worldˈs highest mountain,just becomes more challenging.The government of Nepal is telling climbers they cannot leave trash on the trails.Each climber will have to come down the mountain with at the least 18 pounds of garbage.Thatˈs the average amount of trash a climber leaves behind on Qomolangma.

Officials say climbers are responsible for their own trash.“We are not asking climbers to pick up trash left by someone else,”said the Nepal Tourism Ministry.“We just want them to bring back what they took up.”

More than 4,000 people have reached the 29,035-foot summit（顶峰）in more than 60 years.Leaving trash along the way helps climbers keep their bags light so they have energy to reach the summit.“The trash problem in Qomolangma is not new.”Burlakoti says.“When the people started to climb the mountain,they started to leave their garbage there.”They have left behind bottles,food boxes and equipment.

The new rule came into effect in April,2014.To make sure it is followed,climbers will have to deposit money（交保证金）before they climb.Once they climb back down the mountain,officials will check climbers at a return camp to make sure they have the required 18 pounds of trash.If they do,their money will be returned to them.If they do not,climbers will not receive their deposit and they will not be given a permit the next time they want to climb Qomolangma.

The goal is to make sure no more litter will be left on Qomolangma."As we offer Qomolangma to all the people of the world they should take responsibility to clean it."Burlakoti says,“After seeing the results from this,we will also apply this rule to other mountains.”

Why do men die earlier than women? The latest research makes it known that the reason could be that men’s hearts go into rapid decline when they reach middle age. The largest study of the effects of ageing on the heart has found that women’s longevity(长寿) may be linked to the fact that their hearts do not lose their pumping power with age.

“We have found that the power of the male heart falls by 20-25 percent between 18 and 70 years of age,” said the head of the study, David Goldspink of Liverpool John Moores University in the UK.

“Within the heart there are millions of cells that enable it to beat. Between the age of 20 and 70, one-third of those cells die and are not replaced in men,” said Goldspink. “This is part of the ageing process.” What surprises scientists is that the female heart sees very little loss of these cells. A healthy 70-year-old woman’s heart could perform almost as well as a 20-year-old one’s.

“This gender difference might just explain why women live longer than men,” said Goldspink.

They studied more than 250 healthy men and women between the ages of 18 and 80, focusing on healthy persons to remove the confusing influence of disease.

The team has yet to find why ageing（衰老）takes a greater loss on the male heart, said Goldspink.

The good news is that men can improve the health of their heart with regular exercise. Goldspink stressed that women also need regular exercise to prevent their leg muscles becoming smaller and weaker as they age.

One night, Pilar was in a deep sleep when she was woken by her cat Inti. Inti was meowing wildly outside Pilar’s bedroom and throwing himself against the closed bedroom door. When Pilar opened her eyes, she saw that her bedroom was filled with smoke. As she escaped her house with Inti in her arms, she saw that a fire was burning in her kitchen. Pilar could easily have lost her life, but Inti would not let that happen. Even though Inti could have escaped the house through a cat door, he wouldn’t leave Pilar.

As amazing as this story is, it is not as uncommon as you may think. Take the example of Charlotte Lee and her horse, Thunder. One summer night, the whole family was asleep with the windows open. It was normally very quiet where they lived. Suddenly, there was a loud noise. Charlotte woke up from her sweet dream, and the noise continued. Then she heard a horse running fast towards the house. The next thing she saw was Thunder standing outside her window, neighing(嘶叫) and shaking his head. She knew something was wrong. Charlotte quickly got everyone out of the house before the earthquake hit. Thunder has saved her life.

There are also stories of wild animals coming to the rescue of humans. One animal known to be a friend of humans is the dolphin. Once, Todd Endris was surfing with his friends when he was attacked by a 13-foot(4-meter) shark. In the middle of the attack, a group of dolphins came to his rescue by forming a protective ring around Endris until he could get safely to shore. Without the help of the dolphins, there is little chance that Todd could have escaped.

No one is sure why animals have so often come to our rescue. However, it is clear that humans and animals enjoy a close relationship. It is important that we care for them as much as we can.

Are you sick of going to bed late and waking up tired? Then grab your hiking boots and a tent. A new study suggests that camping in the great outdoors for a couple of days can reset your body clock and help you get more sleep.

The body clock is an internal system that tells our bodies when it’s time to go to sleep and when it's time to wake up. Scientists track this clock by measuring the amount of melatonin (褪黑激素)circulating in a person’s blood at any given time.

In a healthy sleeper, melatonin levels rise a few hours before bedtime, stay high through the night, and then settle back down when it’s time to wake up.

In our modern society，however，most of us stay up many hours past sunset and would probably sleep in many hours after sunrise if we could. And the trouble is，your melatonin levels may still be high when your alarm clock goes off in the morning, which leads to fatigue. It may also have other health consequences as well, such as diabetes (糖尿病)，overweight and heart disease.

Professor Kenneth Wright of the University of Colorado in the US wanted to see if our body clocks can be reset by a short stay in nature. His team recruited (招募)fourteen physically active volunteers in their 20s and 30s. Nine went on a weekend camping trip, while the other five stayed home. At the end of the weekend, the researchers reported that in just two days, the campers’ body clocks had shifted so that their melatonin levels began to rise more than an hour earlier than they did before they left on the trip. By contrast, the body clocks of the group that stayed home shifted even later over the course of the weekend.

“This tells us we can reset our clocks fast,” Wright said.

Therefore, if you want to change your sleep patterns you could try to increase your exposure to natural light during the day and decrease the amount of artificial light you see at night. And if that doesn’t work，there’s always camping.

Next, cover the hole with the plastic sheet, securing the edges of the plastic with dirt and weighting the sheet’s center down with a rock. The plastic should now form a cone(圆锥体) with 45-degree-angled sides. The low point of the sheet must be centered directly over, and no more than three inches above, the cup.

Twelve years ago, a young traveler named Rhett Butler fromSan Francisco,California, visited theSabahrainforest on Malaysian Borneo. In the rainforest, he watched a bird flying through the trees. The beautiful sight left quite an impression on him. But weeks later, back home, Rhett Butler got the news that trees in the area he visited had been cut down.

That experience led Rhett Butler to write a book about rainforests and threats to their existence. But he did not publish the book. Instead, he created a website, using his research for the book. The site is Mongabay.com. His purpose was to inform the public of tropical rainforests. But the subject quickly developed. As a former businessman, he became a respected writer of science and environmental stories.

The popularity of Mongabay.com attracted advertisers. Small ads on the site pay for its operations. Mongabay.com has grown and led to other sites, for example, kids.mongabay.com, a site for children; WildMadagascar.org, which is about the island that Rhett Butler called his favorite place.

To keep his website going, he travels around the world on several major trips each year. His working tools are a laptop computer, cameras and some diving equipment. He often calls on experts for information. For example, he interviewed Alison Jolly, a top expert on lemurs (狐猴). He interviewed Rodney Jackson, a biologist who established the Snow Leopard Conservancy (雪豹保护协会).

Stories like these have made Mongabay a favorite place on the Internet for researchers, students and teachers. In April, Time.com named it one of the fifteen top climate and environment websites in the world.

Cancer is a leading cause of death around the world.

When it comes to cancer, the sooner you know you have it, the better your chances of surviving are.

A new blood test could change the way doctors and researchers find cancer in patients. Researchers say the test could provide some hints of the early forms of the disease.

Gareth Jenkins is a professor at the University of Swansea. He says he and his team did not look for cancer. They instead looked for a by-product of cancer, mutated (突变的) red blood cells. They looked for, what Jenkins calls, the collateral (附带的) damage of cancer—the damage left by the disease.

“In this blood test we don’t measure the presence of cancer，we measure the presence of mutated red blood cells which are the collateral damage that occurs—a by-product of the cancer developing.’’

The researchers used normal laboratory equipment to perform the tests. This equipment looks for changes in the structure of millions of red blood cells. Those mutated cells lack a surface protein (蛋白质) that healthy cells normally have.

“The goal of the test is looking for very rare cells which have picked up a mutation. The number of mutated red blood cells in a healthy person is around 5 or so mutated cells per million; so, you have to look at millions of red blood cells to discover those rare events. The number increases in cancer patients—it goes up to 40 or 50 on average.”

The researchers tested blood from about 300 people, all of whom have cancer of the esophagus (食管). Patients with esophageal cancer have high levels of mutated red blood cells. Jenkins says that at this point he is not sure if other cancers would produce similar results.

The hope is that the new test could one day become part of commonly used medical methods to find out if a person has cancer. These new technologies could save millions of lives.

Can you imagine what things will be like 50 years from now? You’ll get up in the morning and brush your teeth in front of the bathroom mirror just like today. But one thing will be different: besides showing your image, the mirror might also show news, traffic, videos and weather information.

When you are ready to go to work, your smart car will drive you to your office. It knows the best route to take to avoid traffic. You will be able to check your e-mails on the dashboard (仪表盘). Every car will even be able to “talk” to others to avoid accidents.
  The scenes above aren’t just fantasies. They are the latest concepts and inventions presented at last month’s Mobile World Congress, a yearly trade show held in Barcelona, Spain.
  At the show, people were able to experience new technologies and mobile devices (装置) that are highly likely to enter their daily lives in the near future.
  For example, a new fitting room was introduced that lets you try on clothes virtually. It has 360-degree mirrors that create a 3-D image of you in the clothes, and this image can be sent to your phone for you to decide later which items to buy.On the street, photos of products were placed on posters with NFC tags (标签) – a special code (编码) a bit like a 2-D bar code. You could hold your phone up to the tags to add those items to your shopping basket online, pay for them with your phone and have them sent to your home.  As The Guardian noted, the Mobile World Congress shows how electronic devices are becoming smarter by the day. Soon, you might find yourself asking your washing machine: “How are you getting on?” To which it will reply: “Almost there, sir; I’ll be done in 15 minutes.”

     It’s cold and dark outside，and your bed is so warm and comfortable. Going for a run seems like such a bad idea. But before you hide your running shoes，it might be worth giving that crazy idea a go.

  According to The Huffington Post，an outdoor run in winter, as opposed to one on a treadmill(跑步机)，bums more calories because the body is working hard to regulate(调节)its core temperature. Furthermore, research shows that race times are faster in cold weather than in warmer temperatures-and quicker runs burn more calories. Similarly，cold weather also makes the heart work harder to distribute blood through the body，making that vital muscle even stronger.

Outdoor exercise also turns up your energy and rids you of the stress and depression that build up every day. The heat and humidity in the summer can drag you down and tire you faster, but cold weather is refreshing. It adjusts you to your surroundings，making you feel alive.

Of course，the threat of smog in some built-up areas is a further hurdle to winter exercise. Heart attacks stroke, lung cancer and asthma are all dangers of running in smog. The combination of air pollution and exercise increases the potential problems. If you do choose to run outside on smoggy days, take a path in a park or residential area to avoid car exhaust(尾气) and go early in the morning，before rush hour. But staying inside on smoggy days and waiting for the next clear day to run is best.

How many things can you see in the night sky? A lot! On a clear night you might see the Moon, some planets, and thousands of stars.

But scientists believe there are some things in the sky that we will never see. We won’t see them with the biggest telescope in the world, on the clearest night of the year. That’s because they are invisible. They’re the mysterious dead stars called black holes.

 You might find it hard to imagine that stars die. After all, our Sun is a star. Year after year we see it up in the sky, burning brightly, giving us heat and light. The Sun certainly doesn’t seem to be getting old or weak. But stars do burn out and die after billions of years.

 As a star gases burn, they give off light and heat. But when the gases run out, the star stops burning and begins to die. 

As the star cools, the outer layers of the star pull in towards the center. The star squashes(挤压) into a smaller and smaller ball. If the star was very small, the stars ends up as a cold, dark ball. If the star was very big, it keeps squashing inward until it’s packed together tighter than anything in the universe.  

Imagine if the Earth were crushed(挤压) until it was the size of a tiny marble. That’s how tightly this dead star, a black hole, is packed. What pulls the star in toward its center with such power? It’s the same force that pulls you down when you jump--- the force called gravity. A black hole is so tightly packed that its gravity sucks(卷入) in everything---even light. The light from a black hole can never come back to your eyes. That’s why you see nothing but blackness.  

So the next time you stare up at the night sky, remember: there’s more in the sky than meets the eye! Scattered(散落) in the silent darkness are black holes--- the great mystery of space.