Birthdays are strange things. The more you have, the more you try and pretend they don't matter, and the more {#blank#}1{#/blank#} . I'm not really sure why they think so. It's true that you are getting older, but as {#blank#}2{#/blank#} , “Who isn't getting older every day?” The problem may be that a birthday reminds people of all the things {#blank#}3{#/blank#} , but have not. I certainly understand that feeling, though I think {#blank#}4{#/blank#} that I most want to do — a kind of personal re-ordering (重新排序) of the to-do list. What makes you depressed(郁闷) on your birthday is that you realize your re-ordered to-do list is exactly the same as it was last year. That makes you feel{#blank#}5{#/blank#} , and not been anywhere. I have not had that experience this year. I look back at where I was last year and find things have changed since then.

    Members of an international organization are called the Global Greeters. They offer travelers the chance to get to know a city as well as local people do.

    Unlike the professional guides(专业导游), the volunteer greeters act more like neighbours. They take visitors to visit the city–either on foot or public traffic—to discover favourite neighbourhoods, cafes and parks.

    All the programs work a little differently, but the basics(基本项目) are the same. The tours are free and last anywhere for two or four hours. Volunteers can be all ages, and their ages and interests try to match the travelers.

    New York City(USA)

    Big Apple Greeter is the pioneer “welcome visitor” program founded in 1992 by New Yorker Lynn Brooks. More than 300 volunteers now can welcome guests from all over the world in 22 languages. Greeters explain the New York City subway and bus systems and show guests around one or more of their favourite neighbourhoods. Like many greeter organizations, Big Apple accepts online donations to help with its daily costs.

    Houston(USA)

    Houston Greeters will organize activities such as golf, biking or an outing to an Astros game(太空人队的比赛). Another activity is to arrange a tour in need of a particular interest.

    Chicago(USA)

    Chicago Greeters help visitors visit one of the city's many famous neighbourhoods. The group organizes walks through Ukrainian Village on the Near North Side and Andersonville, home to Scandinavian restaurants and shops and Middle Eastern bakeries. Guides will also organize tours around themes such as fashion, film or public art.

    France

    In France, English speaking volunteers for Parisien d'un Jour lead visitors through hidden corners of Paris, often ending with a lively discussion on a café balcony. Guides in Lyon organize walks around themes such as shopping, markets and sports.

    March 20th is World Water Day every year. According to a report from the United Nations, more than half of the world's major rivers have serious water loss and are polluted.

    The Yellow River, the world's fifth longest river, watered some of the oldest farms on earth.

    {#blank#}1{#/blank#}Its source（源头）on Qinghai-Tibet Plateau is drying up. In most of the past 35 years, it didn't reach the sea.

    The Nile in Egypt, running 6, 650 km, is the longest river in the world.{#blank#}2{#/blank#}Now it is down to 2 billion m³ or so. Australia's Murray River reaches the sea only every other year. One fifth of America's Rio Grande has no water, either.

   {#blank#}3{#/blank#}

    Mostly it's damming（筑坝）and global warming that make rivers dry.{#blank#}4{#/blank#}Now about 45, 000 of them lie across the world's rivers. They hold back around 15% of the world's fresh water from running to the sea.

{#blank#}5{#/blank#}Warmer weather takes water away. The glacier（冰川）are becoming smaller. The source of the Yellow River is drying up because of it. Global warming has had certain effects on water sources. Droughts （干旱） happening around the world make people pay more attention to this fact.

     Danny and Jenny are talking about their school science fair. They are very excited. Danny is ready for the big science fair next year. He hopes to win first prize. His project is about silk worms. She is interested in that. She made a video about silk worms. She has a small piece of old silk. She also has a silk worm for the visitors. She thinks silk worms are interesting. What's Danny's project about? It's all about donuts. He talks about the history of donuts. He will make ten different kinds of donuts. You can taste them if you go to the science fair.