It's just been three months after the first bike-sharing company arrived in Singapore, but reports of abuse and vandalism（故意破坏）of shared bikes in the city keep appearing on social media.

    The majority of these shared bikes are stationless, which means they don't need to be stopped at a designated（指定的）spot. They lock themselves after your ride is over, and you're meant to just leave the bike at the side of a road.

    But users have been chaining up bicycles outside their apartments, preventing others from using them. Some people bring them up to their apartment floors, so they can't be found easily by other users. Some people have removed the bikes' number plates or codes, and some even have painted over the bikes to claim the bikes for themselves. Most of the abused bikes belong to either Singapore-based oBike, or ofo, a bike-sharing giant based in China.

    ofo has encouraged Singaporean users to report issues. oBike said that the number of bicycles that were damaged made up less than one percent of its fleet. The company said in February that it planned to bring in “tens of thousands” of bikes by mid-2017. The company has yet to ban anyone from its service, but said that it would take appropriate action – including making reports to the police.

    oBike also introduced a shortcoming system, similar to that of its competitor, China-based Mobike. Users start with 100 points, which get taken away for errant（出格的）behaviour such as forgetting to lock the bike, or parking at non-designated areas. Users are banned from using oBike when their scores reach zero. oBike has an eight-man operation team that can remove bicycles parked casually.

    When approached for comment, Mobike said, “In China, just as in Singapore, there are always a tiny minority of people who abuse the bikes, so we designed our system to prevent this type of abuse.”

    Can exercise during childhood protect you against memory loss many decades later?Exercise early in life seems to have lifelong benefits for the brain,in rats at least.

    "This is an animal study,but it shows that physical activity at a young age is very important一not just for physical development,but for the whole lifelong track of cognitive（认知的）development during ageing,"says Martin Wojtowicz of the University of Toronto,Canada."In humans,it may delay the appearance of Alzheimer's symptoms（阿兹海默氏症）,possibly to the point of preventing them."

    Wojtowicz's team divided 80 young male rats into two equal groups,and placed running wheels in the cages of one group for a period of six weeks.Around four months later—when the rats had reached middle age—the team taught all the rats to connect an electric shock with being in a specific box.When placed in the box,they froze with fear.

    Two weeks later,the team tested the rats in three situations: exactly the same box in the same room,the same box with the room arranged differently,and a completely different box in a different room.

    The rats without access to a running wheel when they were young now froze the same percentage of times in each of these situations,suggesting they couldn't remember which one was dangerous.But those that had been able to run in their youth froze 40 to 50 percent less in both changed box settings.

    “The results suggest the amount of physical activity when we're young,at least for rats,has influence on brain and cognitive health—in the form of better memories—when we're older,"says Arthur Kramer of Northeastern University in Boston,who has found that,in humans,exercise promotes the growth of new brain cells.

    Karen, one of my co-workers, complained about her apartment every day. One day I asked her why she didn't look for another apartment. It seemed like an easy solution to me. Karen's reply to this was, "I will look for another apartment when I come back from vacation."

    Sam hated his job. He had a love for photography and was currently taking a two-year course to obtain his certificate. Every night he complained about his work. I asked him why he didn't finish his course and start a small business doing photography on the weekends. His reply was, "If only I had more time to finish my course. When I finish my course I will start a business."

    Harry worked for a company that allowed early retirement. He had both the years of service and his age, which allowed him to retire, but at a reduced pension. He was having difficulty coping with all the changes that were being made in his work. I was worried about the stress of his job and the effects it was having on his health. "Why don't you retire, Harry? Do something that you have always wanted to do?" I asked. Harry's reply to my question was, "If only I was older then I would get my full pension." "But Harry, you have your house paid off. You have no bills, and the kids are grown up. You can sell your house and get a smaller one. It's really not worth your health, is it? Harry then said, "When the summer comes, maybe I will."

    Now a year later, Karen is still living in the apartment she hates! Sam is still complaining about his job! Harry is still working and his health is not what it used to be! These people had a lot of stress in their lives that they could have taken action to reduce. But all of them defeated themselves by thinking "if" or "when". Life is too short for "if's and when's". The next time you are in a stressful situation and you find yourself saying or thinking "if or when", remember the saying, "If and when were planted and nothing grew!" Change your thinking and take action so that you can reduce your stress right now.

    A recent university study found that current electric cars could be used for 87% of daily car journeys in the US. That figure could rise to 98% by 2020.

One hurdle to the widespread adoption of electric cars has been “range anxiety” —drivers' concerns about running out of petrol on a journey. While petrol stations are conveniently located across national road systems, the necessary network of electric charging stations is still being developed. In fact, charging points are becoming increasingly common throughout the USA.

    Attitudes towards electric vehicles have changed quite considerably over the last few years. Not that long ago, electric cars met with doubt, and their high price drove customers away. Thanks to improvements in battery capacity(电池容量), recharging times, performance and price, the current generation of electric cars is starting to persuade critics.

    As well as progress on the road, electric vehicles are taking to the sea and sky. Electric boats are among the oldest electric vehicles, having enjoyed several decades of popularity from the late 19th to the early 20th century before petrol-powered outboard motors took over. Now, the global drive for renewable energy sources is bringing electric boats back. Steps towards electric planes are also being made, with Airbus and NASA among the organizations developing and testing battery-powered planes. The experiments could soon make electric flight a reality.

    Electric vehicles do not produce any emissions(排放物). Were the US to act on the study's findings and replace 87 percent of its cars with electric vehicles, it would reduce the national demand for petrol by 61 per cent. However, because of the production processes and the generation of electricity required to charge these vehicles, they cannot claim to be completely emission-free. Even so, as many countries continue to increase their use of renewable energy sources, electric vehicles will become even cleaner.

    Traveling can be a fun way to gain life experiences, especially during Spring Break-a week-long school vacation in the United States. But what if you're a student and don't have enough money for a trip？Don't worry. Here are some useful suggestions.

    Save：This probably is the most important preparation for traveling. Cut expenses to fatten your wallet so you'll have more choices about where to go and how to get there.

    Plan ahead：Don't wait until the last minute to plan your trip. Tickets may cost more when bought on short notice. Giving yourself several months to get ready can mean security and savings.

    Do your homework：No matter where you go, research the places you will visit. Decide what to see. Travel books will provide information on the cheapest hotels and restaurants.

    Plan sensibly：Write down how much you expect to spend for food and hotels. Stick to your plan or you may not have enough money to cover everything.

    Travel in groups：Find someone who is interested in visiting the same places. By traveling with others you can share costs and experiences.

    Work as you go：Need more money to support your trip？Look for work in the places you visit.

    Go off the beaten path：Tourist sites may be expensive. You may want to rethink your trip and go to a less﹣known area. Smaller towns can have many interesting activities and sights.

    Pack necessary things：The most important things to take are not always clothes.

Remember medicine in case you get sick, and snacks in case you cannot find a cheap restaurant.

    Use the Internet：The net can help to save money. Some useful websites include www.travelcity.corn, www.bargainslowestfare.corn and www.economictravelcity.com.

    By planning sensibly, even students can enjoy the travel. Your travel experiences will be remembered for a lifetime.