More than 10 years ago, it was difficult to buy a tasty pineapple.The fruits that made it to the UK were green on the outside and, more often than not,hard with an unpleasant taste within.Then in 1966,the Del Monte Gold pineapple produced in Hawaii first hit our shelves.

    The new type of pineapple looked more yellowy-gold than green.It was slightly softer on the outside and had a lot of juice inside.But the most important thing about this new type of pineapple was that it was twice as sweet as the hit-and-miss pineapples we had known. In no time, the Del Monte Gold took the market by storm, rapidly becoming the world's best-selling pineapple variety, and delivering natural levels of sweetness in the mouth,up until then only found in tinned pineapple.

    In nutrition it was all good news too.This nice tasting pineapple contained four times more vitamin C than the old green variety.Nutritionists said that it was not only full of vitamins, but also good against some diseases.People were understandably eager to be able to buy this wonderful fruit.The new type of pineapple was selling fast9 and the Del Monte Gold pineapple rapidly became a fixture in the shopping basket of the healthy eater.

    Seeing the growing market for its winning pineapple, Del Monte tried to keep market to itself.But other fruit companies developed similar pineapples.Del Monte turned to law for help, but failed. Those companies argued successfully that Del Monte's attempts to keep the golden pineapple for itself were just a way to knock them out the market.

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    Scientists are using robots to study the health of waters in and around Venice, Italy. The robots are designed to act like fish, other underwater creatures and plants. The scientists are working with several universities and research centers as part of a group called subCULTron. The European Union gives money to the project as part of its Horizon 2020 program whose aim is to take great ideas from the lab to the market and support science and innovation (创新) in Europe. The scientists want to use the artificial intelligence of the robots to help humans understand what is happening under the water of the Venice lagoon (潟湖).

    SubCULTron, a collective artificial intelligence project, plans to create the biggest shoal (鱼群) of robot fish in the world. The project's aim is to improve knowledge of the seabed and try to turn human abilities into hi-tech items.

    Alexandre Campo, a computer scientist, says the scientists have looked at the way animals learn to work in groups to understand how robots can learn to work together. The subCULTron project wants its robots to learn to work together so they can watch out for changes and new problems in the water.

    One problem the researchers had in the beginning was how the robots would communicate with each other. Wi-Fi and GPS equipment don't work underwater. Instead，the robots can use sonar (声呐) and an electric field.

    Another problem was charging batteries. The robots come up to the water's surface and stay near a boat or a power station to charge without any electrical cables. Besides, how to be water- proof, especially for some key pads of the robots, was really tough. Fortunately, a special mixture has been created to be pinned on the robot, which successfully stands the test of water.

    The health state of the lagoon is pretty good. There are no industrial polluters, and the city now has a modem sewer (污水管) system. It's not like before when all the waste flushed directly into the water. The robots in Venice will continue their work until 2019. The subCULTron project hopes they develop into “an artificial society underneath the water surface” that serves “a human society above the water”.

    The BeiDou Navigation Satellite System（BDS）is a Chinese satellite navigation system. It consists of two separate satellite constellations（星座）. The first BeiDou system, officially called the BeiDou Satellite Navigation Experimental System and also known as BeiDou-1, consists of three satellites, which since 2000 has offered limited coverage and navigation services, mainly for users in China and neighboring regions. Beidou-1 was decommissioned at the end of 2012.

    The second generation of the system, known as COMPASS or BeiDou-2, became operational in China in December 2011 with a partial constellation of 10 satellites in orbit. Since December 2012, it has been offering services to customers in the Asia-Pacific region.

    In 2015, China started the build-up of the third generation BeiDou system（BeiDou-3）in the global coverage constellation. The first BDS-3 satellite was launched on 30 March 2015. Up to January 2018, nine BeiDou-3 satellites have been launched. BeiDou-3 will eventually consist of 35 satellites and is expected to provide global services upon completion in 2020. So far, China has sent 27 BeiDou satellites into space. When fully completed, BeiDou, the world's fourth navigation satellite system, following GPS in the United States, GLONASS in Russia and Galileo in the European Union, will provide an alternative global navigation satellite system to the United States owned Global Positioning System（GPS）, and is expected to be more accurate than the GPS. It was claimed in 2016 that BeiDou-3 will reach millimeter-level accuracy（with post-processing）, which is ten times more accurate than the finest level of GPS.

    According to China Daily, in 2015, fifteen years after the satellite system was launched, it was generating a turnover of $31.5 billion annually for major companies such as China Aerospace Science and Industry Corp, AutoNavi Holdings Ltd, and China North Industries Group Corp.

    A new study, a project of the researchers from the University of Pittsburgh in Pennsylvania, finds the fitness tracker probably does not help with weight loss.

    The devices are designed to record your physical activity. They are usually worn around the wrist, where they measure a person's heart rate. The research team looked at two groups of individuals. The first wore a fitness tracker and took part in health counseling (咨询) with experts to consider the best weight-loss plan. The researchers compared this group with people who only got health counseling.

    The study found that those only speaking with the health experts lost nearly 6 kilograms, but those using a fitness tracker lost only 3.5 kilograms. John Jakicic, the lead researcher, questioned the use of electronic devices for weight control in place of "effective behavioral counseling for physical activity and diet."

    The study involved 470 subjects aged between 18 and 35. Some of them were overweight, while others were considered obese (肥胖的). Over three fourths of the subjects were women. All the subjects were told to increase physical activity and start on a low-calorie diet. They had their weight measured once every six months. After six months, researchers divided the group into two parts: one continued with monthly counseling, while members of the other group were given a fitness tracker. Eighteen months later, both groups "showed significant improvements in fitness, physical activity, and diet," with no major difference between groups. However, when it came to losing weight, the people who only spoke with experts lost nearly twice as much weight.

    Jakicic said, "the study's findings are important because effective long-term treatments are needed to address America's obesity." More information is needed, he added, to learn how to best use these devices to change "physical activity and diet behaviors" in adults who want to lose weight.

    Albert Einsein said," Only a life lived for others is worth living."

How does this job offer sound? You'll need to be available on short notice，including late at night and on weekends. You could be asked to do anything from helping at community events to responding to life-threatening emergencies (sometimes putting your own safety at risk). This job also involves a lot of regular training. Oh, and you won't be paid for any of this. Would you take the job?

    This job might not necessarily appeal to everyone, but if this sounds like an opportunity you'd eagerly accept，then you'd fit right in with Western Australia's 26,000 emergency service volunteers. The emergency services aren't the only industry benefiting from volunteers. Across both Australia and America, between a quarter and half of the population volunteer each year in areas including education, sports, health, religion, and social services.

    What motivates people to volunteer? Yes, volunteers don't get paid. But it doesn't mean people don't get benefits from volunteering. Indeed, research shows there are significant mental health benefits coming with volunteering. It can be a means to make new friends, build new skills or try things out of your comfort zone. It can also be a means to help loved ones. A case is someone close to me who recently lost her husband to a disease. When her husband was admitted to a nursing facility, she decided to volunteer for the patient advocacy committee. She found great support and felt she could make a difference in the lives of the patients. After her husband's passing, she decided to continue volunteering for the committee not only as a way to show gratitude for the great care her husband received but also because she made friends there. She found a way to put her career skills to use for the common good and keep active after retirement.

    There are countless ways to volunteer. No matter how you do it, it is definitely worth every minute you put into it.

    My teacher held up a piece of broken glass and asked, "Who broke this window?"

    Thirty boys tried to think about not only what they had done, but also what our teacher may have found out. She seldom became angry, but she was this time.

    "Oh," I thought. I was the one who broke the window. It was caused by a naughty throw of a baseball. If I admitted guilt, I would be in a lot of trouble. How would I be able to pay for a big window like that? I didn't even get an allowance. "My father is going to have a fit." I thought. I didn't want to raise my hand, but some force much stronger than I was pulled it skyward. I told the truth. "I did it." It was hard enough to say what I had.

    My teacher took down a book from one of our library shelves and I had never known my teacher to strike a student, but I feared she was going to start with me.

    "I know how you like bird," she said as she stood looking down at my guilt-ridden face. "Here is that field guide about birds that you are constantly checking out. It is yours now. It's time we got a new one for the school anyway. You will not be punished as long as you remember that I am not rewarding you for your misdeed, I am rewarding you for your truthfulness."

I couldn't believe it! I wasn't being punished and I was getting my own bird field guide—the very one that I had been saving up money to buy.

    All that remains of that day is my memory and the lesson my teacher taught me. That lesson stays with me every day, and it will echo forever.