1 . When my son, Mark, was in the third grade, he saved all his pocket money for over three months to buy Christmas presents. The third Saturday in December Mark said he had made his list and had twenty dollars in his pocket.

I drove him to a nearby supermarket. Mark picked up a basket and went in while I waited and watched in the car. It took Mark over 45 minutes to choose his presents. Finally he came to the checkout counter and reached into his pocket for his money. It was not there! There was a hole in his pocket, but no money. Mark stood there holding his basket tears falling down his face.

Then a surprising thing happened. A woman came up to Mark and took him in her arms. “You would help me a lot if you let me pay for you” said the woman. “It would be the most wonderful gift you could give me. I only ask that one day you will pass it on. When you grow up, I would like you to find someone you can help. When you help others, 1know you will feel as good about it as I do now.”

Mark took the money, dried his tears and ran back to the checkout counter as fast as he could. That year we all enjoyed our gifts almost as much as Mark enjoyed giving them to us.

I would like to say “thank you” to that very kind woman, and tell her that four years later Mark went house to house collecting blankets and clothes for the homeless people in the fire. And I want to promise her that Mark will never forget to keep passing it on.

2 . City: Hangzhou

Launched: 2008

Size: 2,965 stations/ 69,750 bikes

Price: $28.59 deposit(押金) + time charge

While taking a look at this city, you may see the best bike sharing in the world. As the second on the planet by size, the Hangzhou Public Bicycle System is one of the most common and useful shares, largely because it’s combined with public transportation: a single card can be used in subway, bus, taxi and bike sharing. Residents and tourists can put down a deposit of 200 Chinese Yuan (about $29) and ride for an hour for free in this scenic city. Each additional hour costs only $0.15. It was also the first new-generation bike-sharing system in China.

City: Barcelona

Launched: 2007

Size: 420 stations/6,000 bikes

Price: $61.93 per year

Barcelona’s Bicycling Program developed Spain’s bike-sharing business in a big way. This program took off like wildfire on wheels, and because four times bigger in one year. It inspired different copycat programs all over the country. Today, Spain has 132 bike-sharing systems. The program is one of the world’s most respected and popular shares. But it is only open to residents and tourists are not allowed to use them.

City: Paris

Launched: 2007

Size: l,751 stations/23,900 bikes

Price: $38. 52 per year/ $2.26 per day

Bike sharing in Paris is the star of the world. Launched in 2007, it is the world’s largest outside of China. Cheap by American standards, you can ride around Paris on a $1.7 day pass—the first half hour of each trip is free. Because this system covers the city with an average of 50 stations per square mile, it’s a favourite with both locals and tourists.

3 . A new study suggests that dark markings on the planet Mars represent sand — not water. The research in 2015 suggested that lines on some Martian hills were evidence of water. Yet American scientists now say these lines appear more like dry flows of sand. If water is present, it is likely to be a small amount. Water in liquid form would be necessary for microbial (微生物的) life.

NASA, the American space agency, said more research is needed. Michael Meyer is the lead scientist for NASA’s Mars exploration programme. He noted that the latest study does not reject the presence of water. But he admitted, “It just may not be as exciting as the idea of rivers going down the sides of cliffs (悬崖).”

The new findings come from a team led by Colin Dundas of the United States Geological Survey. His team measured 151 of these lines in 10 areas. Most of the lines end with slopes (倾斜) between 28 degrees and 35 degrees. These measurements are similar to active sand dunes (沙丘) on both Mars and Earth. A small covering of dust that moves and sometimes becomes lighter might help explain the markings. They usually appear in the Martian summertime, and then disappear until the next year. If these lines are dry, this suggests that recent Mars bas not had large amounts of liquid water. Dundas and his research team say that many questions remain.

“I still think that Mars has great potential for having had life early on in its history,” Meyer said. “As long as that’s true, we also have a reasonable possibility of life still being on Mars. It just happens to be cryptic or well hidden.”

NASA currently has no robotic — either on Mars or in development — with the ability to climb steep slopes. The lack of such equipment has engineers coming up with ideas like Martian helicopters or planes without pilots.

4 . In summer, millions of people will head for the beach. And while the ocean can be a great place to swim and play, it may also be useful in another way. Some scientists think that waves could help make electricity.

“Have you ever been on a surfboard or boat and felt yourself being lifted up by a wave? Or have you jumped in the water and felt the energy as waves crashed over you?” asked Jamie Taylor of the Wave Energy Group at the University of Edinburgh in Scotland. “There is certainly a lot of energy in waves.”

Scientists are working on using that energy to make electricity．

Most waves are created when winds blow across the ocean. “The winds start out by making little ripples (波纹) in the water, but if they keep on blowing, those ripples get bigger and bigger and turn into waves,” Taylor said. “Waves are one of nature’s ways of picking up energy and then sending it off on a journey.”

When waves come towards the shore, people can set up dams or other facilities to block the water and send it through a large wheel called a turbine (涡轮). The turbine can then power an electrical generator (发电机).

The United States and a few other countries have started doing research on wave energy, and it is already being used in Scotland.

The resource is huge. We will never run out of wave power, besides, wave energy does not create the same pollution as other energy sources, such as oil and coal.

Oceans cover three quarters of the earth’s surface. That would make wave power seem perfect for creating energy around the world. There are some drawbacks, however.

Jamie Taylor said that wave power still cost too much money. He said that its effects on animals in the sea were still unknown. Plus, wave power would get in the way of fishing and boat traffic.

With more research, however, “many of these problems might be overcome,” Taylor said. “Demand for energy to power our TVs and computers, drive our cars, and heat and cool our homes is growing quickly throughout the world．Finding more energy sources is very important, for traditional sources of energy like oil and gas may run out some day.”

In the future, when you turn on a light switch, an ocean wave could be providing the electricity!

5 . Have you ever thought of quitting your job when you feel exhausted? Maybe most of you would say “yes”. After a particularly busy period at work, I decided to get away from it all by going on a hike in the mountains in southern France.

Before I left, I read an interesting story in a magazine. It read, “Once, while I was riding on a crowded bus, the man sitting next to me threw his cell phone out of the window when his phone rang. I was surprised. He looked at me, shrugged (耸耸肩) and looked away. I had no idea whether it was his or stolen or whether he even knew what a cell phone was or not, but he clearly wanted to be free of it, because it clearly troubled him.

Billions of people across the world use cell phones. Though cell phones are a wonderful way for communication, they often do the exact opposite. Using cell phones can increase stress within families and friends.

So when I recently returned home, I got rid of my cell phone. Now I go outside without taking my phone with me. I’ve noticed things in my neighborhood I never noticed before, such as gardens. I’ve met new people, started conversations with neighbors I didn’t speak to before and talked with some of my friends face to face instead of chatting over the phone. Instead of keeping me off from the world, stopping using my cell phone has helped me get even closer to my family and friends.

6 . Forcing waiters and waitresses to survive on tips from customers rather than normal wages is a pointless, offensive, and unique American custom that, in the past several years, a handful of progressive restaurant owners have attempted to abolish. Danny Meyer, CEO of Union Square Hospitality Group, is about to join their ranks and has announced that he plans to gradually stop tipping at the company’s thirteen restaurants.

What, exactly, is wrong with tipping? As Brian Palmer has explained, more or less it’s everything. To start with, leaving a waiter’s pay in the hands of customers has a feeling of classism (阶级歧视) . And in theory, handing restaurant customers the power to tip is at least supposed to motivate better service. This fails in practice because humans turn out to be pretty casual about their tipping behavior. Research has shown that the amount diners tip has very little to do with their level of satisfaction. All of this doesn’t encourage waiters and waitresses to do anything but turn over as many tables as possible.

Tipping is also very unfair to kitchen staff. The law allows restaurants to divide tips between front-of-the-house workers like waiters, hosts, hostesses, and bartenders, but not cooks. This creates a system in which the people serving the food in a restaurant can earn more than the people preparing it.

One of the most fascinating parts of Meyer’s move is that, unlike some restaurant owners who have taken an anti-tipping stand, he won’t simply add a standard extra charge to diners’ bills. Rather, Union Square Hospitality Group means to raise menu prices enough to fully cover the cost of a meal. If Meyer manages to move away from tipping at all without hurting his profits, it would almost certainly set the stage for others to follow suit.

7 . In summer the extreme heat often makes people sweaty and restless. While people are annoyed by it, experts suggest summer is the best season to release your body’s toxins (毒素) and recover your energy.

One popular option is hot-stone massage (按摩). Therapists use smooth and heated stones, usually river rocks, to massage certain parts of the body, or place them on key points of the body. The warmth of the hot stones will improve blood circulation and also help relax muscles, while sweating is also believed to be good for releasing the body’s toxins.

Another popular option is hot-stone baths. The hot-stone bath will help the body release toxins and humidity that accumulated during the last winter. Summer is the best season to build a good body. Rather than use water or steam to heat and wash the body, people simply wear a coat or something comfortable, and then lie on heated stone tablets, which are warmed to around 45℃. The body will gradually warm up and blood circulation will also be improved. More sweat will come out quickly. The sweat is smooth and fresh, not smelly like that released after sports activities. Such baths bring a number of health benefits, such as anti-aging, improved blood circulation and stress relief. The slimming effect of dieting can even be promoted.

Using hot stones for healing dates back to ancient times, but the modern renewal of hot-stone massage is generally thanks to Mary Nelson, a native of Tucson, Arizona, America, whose trademark is “LaStone Therapy”.

The therapy (疗法) is gaining wide popularity with many people, especially those who have jobs in cool air-conditioned rooms. The hot-stone therapy can help cure many diseases, including back pain.

8 . For centuries, elephants have played a big role in the world’s economies, culture and religion. The African elephants used to be found all over Africa and the Asian elephants moved from Syria to China to Indonesia. Nowadays, elephants are found in small groups in the south of the Sahara Desert and scarcely in Southeast Asia, Sri Lanka and India.

In the early twentieth century, there were close to ten million elephants, and now the elephant number is as low as 252, 000 and expected to drop down to 160, 000 by 2025. Between 2007 and 2014, the elephant population fell by at least 30%, or 144, 000 elephants. As researchers have traveled over the African plains, they only spotted one herd of 36 elephants in an area like the size of Mexico. It is clear that these gentle mammals are disappearing right before our eyes.

There are many reasons why the elephant population has been decreasing,one of which is their habitat. Humans are competing with elephants for living space, and as more and more humans clear the land that is being used by elephants, the elephants have less space. Elephant hunting or “poaching” has been a major factor for the disappearance of this species, and they are killed only for their valuable ivory tusks. Although the trade of tusks is illegal, it is still a common practice in many places.

Often, all the local people living among elephants would be farmers, and found that they could make more money by selling the tusks of one elephant, than doing manual labor for twelve years. That alone makes it really hard to prevent them from killing the elephants.

Some places such as Botswana, have put in extra effort to protect their wildlife from poachers by founding their Botswana Defense Force, which is made up of around 700 specially-trained soldiers that are stationed in 40 different areas. You may feel worried about the present situations elephants are in, but there are ways to help. To find out how you can help elephant conservation, adopt an elephant, or donate, click here.