Have you ever wondered why birds sing? Maybe you thought that they were just happy. After all, you probably sing or whistle(吹口哨) when you are happy.

    Some scientists believe that birds do sing some of time just because they are happy. However, they sing most of the time for a very different reason. Their singing is actually a warning to other birds to stay out of their territory.

    Do you know what a “territory” is? A territory is an area that an animal, usually the male, claims as its own. Only he and his family are welcome there. No other families of the same species(物种) are welcome. Your yard and house are your territory where only your family and friends are welcome. If a stranger should enter your territory and threaten you, you might shout. Probably this would be enough to frighten him away.

    If so, you have actually frightened the stranger away without having to fight him. A bird does the same thing. But he expects an outsider almost any time, especially at nesting(筑巢) season. So he is screaming all the time, whether he can see an outsider or not. This screaming is what we call a bird's song, and it is usually enough to keep an outsider away.

    Birds sing loudest in the spring when they are trying to attract a mate（配偶）and warn others not to enter the territory of theirs.

    You can see that birds have a language all their own. Most of it has something to do with attracting mates and setting up territories.

    Welcome to your future life!

    You get up in the morning and look into the mirror. Your face is firm and young-looking. In 2035, medical technology is better than ever. Many people your age could live to be 150, so at 40, you're not old at all. And your parents just had an anti-aging(抗衰老的) treatment. Now, all three of look the same age!

    You say to your shirt, “Turn red.” It changes from blue to red. In 2035, “smart clothes” contain particles(粒子) much smaller than the cells in your body. The particles can be programmed to change clothes' color or pattern.

    You walk into the kitchen. You pick up the milk, but a voice says,“ You shouldn't drink that!” Your fridge has read the chip (芯片) that contains information about the milk , and it knows the milk is old . In 2035, every article of food in the grocery store has such a chip.

    It's time to go to work. In 2035, cars drive themselves. Just tell your “smart car” where to go. On the way, you can call a friend using your jacket sleeve. Such “smart technology” is all around you.

    So will all these things come true? “For new technology to succeed,” says scientist Andrew Zolli ,”it has to be so much better that it replaces what we have already.” The Internet is one example—what will be the next?

    It's the holiday season, the time when we connect with family and friends. Social media sites like Twitter and Facebook are full of festive pictures, featuring parents' catching and sharing those special family moments, their child's wish list, and maybe even a cute video of their child dancing to “Jingle Bell Rock” while wearing a diaper (尿片) and Santa hat. Swelling with pride, parents can't wait to get approval with a “thumbs up” or better yet a personalized message on their treasured post.

    Adults should be able to post what they want online. However, when exposing family moments online, are they sharing too much information? Do parents have the right to share those cute now, but embarrassing later moments about kids? Have children willingly given their agreement to sharing their cute but funny video online?

    A recent study found that 75% of parents turn to social media for parenting-related information and social support. There is even a term used to describe the overuse of sharing too much information about kids on social media: “sharenting”. Research also finds that “sharenting” isn't going anywhere anytime soon. What's troublesome is that a typical parent has about 150 Facebook friends and only a third of them are actual friends. So that brings up good questions – Who are we really sharing our information with and why? Who knows when and where that photo could resurface in the future?

    While there's no reliable information on how young children feel about things posted online, we do have information about how teens feel. According to a report by the Family Online Safety Institute, 76% of teens are concerned about their privacy. Many teens constantly search for new apps that allow anonymity. When names are required, they use screen names that don't reveal real information. If our teens are doing a better job of protecting themselves online, shouldn't parents take the lead and do the same? Plus, with more and more college admission representatives and potential employers surfing the internet for potential candidates, we'd hate for one of our posts to change an important decision. Think about it … online reputations are now becoming inseparable with real life ones.

    Of course, we can secure our privacy settings, only allowing our friends to view pictures, posts and videos, but that doesn't stop others from uploading our pictures. Adults need to be cautious of sharing information online, especially information about children.

    So, this holiday season, enjoy family time and share those special memories with family and friends. Before clicking the app to upload photos or videos, stop and think twice.

    Philadelphia, Pennsylvania w America's fifth largest city. Once a major American colonial city, it is the home of America's first library, its first hospital, and its first zoo. Now it is also the first US city to be named a World Heritage City. On November 6, 2015. Philadelphia joined more than 260 other cities that have been recognized for their influence on the world. These cities include Paris, France Florence, Italy and Cairo Egypt.

    "Today marks the start of a new and exciting chapter in the history of Philadelphia" remarked Philadelphia Mayor Michael Nutter when the announcement was made. “As a World Heritage City. Philadelphia is being officially recognized on the global stage for its wealth of contributions to the world. ”

    To be named a World Heritage City, a city be home to a UNESCO World Heritage site are selected for their universal value and significance. For Philadelphia, the site is Independence Hall.

    Independence Hall is where two of the most important documents, approved in US history - the Declaration of Independence and the US Constitution-were adopted. The Declaration of Independence, approved on July 4 1776, united the 13 former British colonies and declared them independent from British rule. The US constitution, signed in 1787, established the American democratic system of government. Democracy is a system of government in which the people elect their leaders. The Constitution later spelled out basic freedoms American citizens have.

    Philadelphia Deputy Mayor Alan Greenberger says the city's selection as a World Heritage City also reflects ta its educational, cultural, and economic achievements. The city is home to dozens of colleges and universities, and many museums, such as the Philadelphia Museum of Art.“Philadelphia has rightfully earned its place as one of the greatest cities in the world.” Greenberger says.

    Tennis lessons

    This event takes place every Wednesday from May 9 to July 17. These lessons are open to all from complete beginners to seasonedpros (熟练的行家). Playing tennis is a great way of getting fit. Contact The Bridge to find the time for your age group.

    Cost: £4.80 adults, £3.30 under 16 per class

    Contact: Laura Reynolds

    Tel: 020 8778 7158

    Street dance classes

    This event takes place every Wednesday from February 27 to December 25. The classes are set up for 3 to 6-year-olds. They provide an environment where each child can become confident in his or her efforts and successes. Our school believes “If You Aim High You Will Succeed”.

    Cost: £4 per student

    Contact: Hayley Rea

    Email: info@aimhighacademy.co.uk

    Children's workshops in clay(陶土)

    This event takes place every Monday, Tuesday, Wednesday and Friday from April 15 to July 1. The workshops are suitable for children aged five years and above. The children will be shown different methods of making many things in clay.

    Cost: £75 for 10 lessons

    Contact: Shirley Stewart

    Email: shirli_stewart@yahoo.com

    Caterpillar(毛毛虫) music

    This event takes place every Tuesday and Friday from October 18 to December 31. The classes are set up for 0 to 4-year-olds. We use puppets (木偶), actions, songs, instruments and games to entertain and introduce a love of music to your little one. The classes last 40 minutes and each week we have a different theme.

    Cost: £6 per class

    Contact: Angela Capriati

    Tel: 020 8698 8439

    Telling fewer lies benefits people physically and mentally. Anita E. Kelly, study author and professor of psychology at the University of Notre Dame, employed 110 adults for her study. She divided them into two groups and asked one group to stop lying for 10 weeks. Lies included big ones and tiny ones—any false statements—but participants were still allowed to leave out the truth, keep secrets and avoid questions they didn't want to answer, etc. The other group wasn't given any special instructions about lying.

    It turned out that both groups reduced their lying, but those who were specifically told to tell the truth improved their health more. "We found that the participants could purposefully and dramatically reduce their everyday lies. That in turn was associated with significantly improved health," said Kelly.

    When participants in the no-lie group told three fewer white lies than they did in other weeks, they experienced, on average, fewer mental-health complaints and physical complaints. They were less likely to feel tense or sad and also experienced fewer sore throats and headaches. They also reported that personal relationships improved. Additionally, participants found themselves honest about their daily accomplishments, and they stopped making up excuses for being late or failing to complete a task, for example.

    "It's certainly a worthy goal to have people be more honest and interact with others in a more honest way,” says University of Massachusetts psychologist Robert Feldman. “That would be beneficial. I'm a little doubtful whether it makes us all healthier, but it may make us healthier in a psychological way."