I really love my job because I enjoy working with small children and like the challenges and awards from the job. I also think my work is important. There was a time when I thought I would never have that sort of career.

    I wasn't an excellent student because I didn't do much schoolwork. In my final term I started thinking what I might do and found I didn't have much to offer. I just accepted that I wasn't the type to have a career.

    I then found myself a job — looking after two little girls. It wasn't too bad at first. But the problems began when I agreed to live in so that I would be there if my boss had to go out for business in the evening. We agreed that if I had to work extra hours one week, she'd give me time off the next. But unfortunately, it didn't often work out. I was getting extremely tired and fed up, because I had too many late nights and early mornings with the children.

    One Sunday, I was in the park with the children, and met Megan who used to go to school with me. I told her about my situation. She suggested that I should do a course and get a qualification（资格证书）if I wanted to work with children. I didn't think I would be accepted because I didn't take many exams in school. She persuaded me to phone the local college and they were really helpful. My experience counted for a lot and I got on a part-time course. I had to leave my job with the family, and got work helping out at a kindergarten.

    Now I've got a full-time job there. I shall always be thankful to Megan. I wish I had known earlier that you could have a career, even if you aren't top of the class at school.

    Aging brings wrinkles, sagging bodies and frustrating forgetfulness. But getting older is not all bad for many people. Mounting evidence suggests aging may be a key to happiness. There is conflicting research on the subject, however, and experts say it may all boil down to this: Attitude is everything.

    Older adults tend to be more optimistic and have a more positive outlook on life than their younger and stressed opposites. The big question is why seniors are happier. A recent study suggests one reason: Older adults remember the past through happy memories. Aging can bring more cheer as people become more comfortable with themselves and their roles in society. The older adults said they were enjoying more time with their family, spending more time on hobbies and having greater financial security and did not have to work.

    But others are doubtful about the link between happiness and growing older.

    "The notion that those in old age are happiest is misleading," said Richard Easterlin, a professor of economics at the University of Southern California. "It is based on comparing people of different ages who are the same in terms of income, health, family life." Easterlin added, "When you take account of the fact that older people have lower income than younger, are less healthy, and more likely to be living alone, then you will find it hard to accept that they are happier.

    In fact, scientists have found that as people age, their health declines and social networks disappear as their friends die, which can make the elderly less happy.

    Even if one does give in to age's dark side, health and happiness don't always go hand-in-hand. It's all about attitude. Research by the University of Chicago's Yang suggests that attitude about life and happiness, is partly shaped by the era in which a person was born. It turns out that individuals who adapt the best to changes also have the highest expected levels of happiness.

 Despite the conflicting findings about aging and happiness, the good news is that there doesn't appear to be a limit to how much happiness one can achieve in one's life. “Most people desire happiness,” Easterlin said. “To my knowledge, no one has identified a limit to attainable happiness.”

    Many years ago, people relied on the sun, the moon and stars to find their way around. Later, the compass was introduced. And now, we have satnav（卫星导航）systems to guide us. A satnav system uses groups of satellites to show the user's location. They send information to a receiver, such as a smart phone, to show us where we are.

    The earliest built satnav system is the Global Positioning System, which belongs to the US. Then there is Russia's Global Navigation（导航）Satellite System, the European Union's Galileo and China's own satellite navigation system, BeiDou.

    On October 14, 2017, an ARJ21-700 plane, which was the first domestically-produced jet equipped with the BeiDou navigation system, successfully completed a test flight. The results showed the performance of the system developed by China matches that of similar systems produced abroad, according to the Commercial Aircraft Corporation of China.

    Since its introduction in 2000, the Beidou navigation system has seen increasing numbers of applications linked to everyday life, from shared bikes to farming.

    When it comes to shared bikes, smart locks that support BeiDou chips offer more accurate positioning than others, making it easier to find a bike.

    Farmers can use BeiDou-enabled tractors to plow（犁）the soil and use unmanned aircraft with BeiDou to sow seeds, which can improve efficiency and make better use of resources. BeiDou's farming applications have spread from Heilongjiang province to Beijing, Liaoning, Shanxi, Hubei and other regions across China.

    With its many uses, the Beidou navigation system is even playing a big role in the Belt and Road Initiative（— 带—路）. “To date, the BeiDou system has covered most parts of the Asia-Pacific region, as well as counties along the Silk Road Economic Belt and the 21^st Century Maritime Silk Road” said Yang Changfeng, Chief designer of the BeiDou system.

    Today, there are more than 20 BeiDou satellites above our heads, and China plans to launch even more this year to expand the BeiDou network to better serve the Belt and Road Initiative.

    “As BeiDou expands its overseas reach, it will be increasingly popular in the logistics （物流）industry,” said Miao Qianjun, secretary-general of the navigation services association. “Ships, for example, can use it to position themselves while sailing across oceans to European countries, no longer limited to Southeast Asian regions in the near future.”

    A recent study led by researchers from the National University of Singapore(NUS)has found a clear link between the color of a taxi and its accident rate. An analysis of 36 months of detailed taxi, driver and accident data from two fleets of yellow and blue taxis in Singapore suggested that yellow taxis have fewer accidents than blue taxis. The higher visibility (能见度)of yellow makes it easier for drivers to avoid getting into accidents with yellow taxis, leading to a lower accident rate.

    The study was led by Prof Ho. To test whether there was a causal relationship between the color of a taxi and the number of accidents the taxi had, the research team analysed data collected by the largest taxi company in Singapore. The researchers found that yellow taxis have about 6.1 fewer accidents per 1,000 taxis per month.

    The researchers also studied the economic effect of changing the color of the entire fleet of taxis to yellow. The Singapore taxi company involved in the study owns about 16,700 taxis in a ratio(比例) of one yellow to three blue taxis. If a commercial decision is made to switch from blue to yellow taxis, 76.6 fewer accidents would occur per month or 917 fewer accidents per year. Assuming an average repair cost of $1,000 per car and a downtime of six days, switching the color of all taxis to yellow could produce an annual savings of $2 million.

    “We are eager to continue to validate(证实) the findings of our study by looking at the use of yellow in other types of public transport, such as school buses. For instance, we hope to compare the accident rates of yellow school buses against other colors to find out if yellow is indeed a safer color for school buses. Besides, we are also interested to look at private-hire vehicles and do a comparison of the accident rates of vehicles that are of different colors,” explained Prof Ho.

    As the weekend approaches, perhaps you're looking forward to a meal out or sitting in front of the TV with a takeaway. But as you settle down to enjoy that comforting plate of beef or start spooning that fragrant lamb curry over the rice, will you be worrying about whether you are really eating what was written on the menu?

    Yesterday it was revealed by the Food Standards Agency that more than a fifth of the 665 meat samples tested last year contained DNA from animals not listed on the label. Of the 145 problem samples, 73 came from supermarkets, while 22 came from processing plants. The remaining 50 all came from restaurants.

    I have no doubt that over the next few years, the percentage of meal coming from dubious origins will continue to rise unless something drastic is done. Why? There are two main reasons. First, too many businesses are willing to boost their profits by adulterating their products in the meat industry. I believe there is a systemic problem within the meat industry that makes it particularly attractive to unscrupulous characters who are really nothing more than criminals，the second is the complexity and length of the meat supply chain. If you buy a chicken-based ready meal from a supermarket, as you might imagine, that chicken will pass through many hands before it ends up on your plate here. Worse still, the meat will often he partially processed somewhere along that chain—usually with salt and water added to boost flavour and volume—which is quite legal.

    Obviously, it is impossible for consumers to be detectives about every piece of meal they eat.

    However, what you can do is to avoid processed foods and never buy ready meals. Stay away from burgers made in factories. Don't go to chain restaurants. Instead, go to local, independent restaurants where it is more likely the chef and owner—often the same person—cares about where the meat comes from, and will be happy to tell you. So, try to buy your meat from a good local butcher.

    And no, what I am suggesting is not going to hurt your purse or wallet. The essence, then, is to buy meat that has had as small a journey from field to fork as possible, because that is the only way you can he sure of what you eat. It's that simple.

    One night I received a Facebook message from Laura, a former classmate. "Hey Steve," she said, "I know you've always been an animal lover. I've just had a baby and I can't keep my mini pig."

    Being fond of animals, I knew I wanted the pig. I just had to figure out how to make it happen. I lived in a two-bedroom single-level house in Georgetwon, Ontario. It's tough to bring a pig back to the house I share with two dogs, two cats, and my lifelong partner.

    But I was not letting that pig go. So I told Laura I'd take the animal. When I got home with the pig, I hid her in the bedroom, and began to prepare a dinner for Alisha—her favourite bacon cheeseburgers. It's better to make her happy before introducing the new member to her.

    When I led her to the bedroom and showed her the surprise, Alisha stood in the doorway like a statue. It took her a few seconds to know what I had done. She complained about my unreasonable action. She insisted there was no more room in the house.

    I knew I was wrong, but I hoped I could smooth things over. Soon enough, the lovely pig did the smoothing for me. Never had we felt such joy as she brought to us. We got her a name "Esther".

    Esther's arrival changed our lives. A few weeks later, we decided to stop eating bacon. We figured it was our turn to try to change the world for other animals. A few months later, we moved to a farm where we cared for abandoned animals—so far, six rabbits, six goats, two sheep, one horse, three cows and three chickens.