Paris

Passengers carried per day: 4.4m

Cost of ticket: 80p flat fare

Length: 131 miles    Lines: 14   Stations: 297

    In Paris there are pleasures for those who use the Metro(地铁) — many of them artistic. The graceful Art Nouveau dragon-fly entrances are just the most noticeable on a Metro system which celebrated its 100^th anniversary by spending 30 million francs (£2.9million) on making its stations works of art. On my way home I pass Bonne Nouvelle station in the heart of Paris's cinema district. There, during the cinema festival this summer, special lighting effects dot the platforms and films are projected onto the large advertising boards.

    More than anything the metro is efficient. “When I worked on line 4”, says a retired driver, “we had exactly 30 minutes and 15 seconds to complete the journey. If it took any longer, they cut our pay.” But there are problems. Many Metro stations have too many stairs, and changing lines at big interchanges(交换) can be tiresome.

Moscow

Passengers carried per day: 9m

Cost of ticket: 12p

Length: 164 miles    Lines: 11   Stations: 162

    The first underground passage for the Moscow Metropolitan started in 1932. Three years later the trains started running. They haven't stopped since— every 90 seconds or two minutes during rush hour, every five minutes the rest of the time, from 6 a.m. till 1 a. m. There may be a crowd of people but there is seldom a wait.

    The trains take you through spacious and spotless stations. For tourists it's a major sightseeing attraction: from Russian Art Deco to neo-classical, the Metro stations are not to be missed.

Tokyo

Passengers carried per day: 7m

Cost of ticket: 90p ~ £1.68

Length: 177 miles    Lines: 12   Stations: 209

    Trains do not just arrive on time in Tokyo. They stop right on the platform mark so that passengers can line up knowing exactly where the doors will open. Train driving is a respectful job for life, for which the applicants must pass a strict screening of health checks, interviews and written exams before they can put on the enviable uniform, cap and white gloves.

    However, overcrowding means it is far from perfect. At rush hours, some stations employ part-time platform staff to push in passengers. Carriages can be filled to 184% of capacity(容量). The main reason for such conditions is that the Tokyo subway station system has only 15 miles of track for every 1 million people, compared to 36 on the London Underground. New lines are under construction, but at a cost of £500,000 per meter of rail. Progress has been slow.

Mexico City

Passengers carried per day: 4.2m

Cost of ticket: 11p flat fare

Length: 99 miles    Lines: 11   Stations: 175

    Fast, relatively safe, and very cheap, Mexico City's underground is an ideal place of order and efficiency compared to the disorders above. The Mexican capital's underground system is the biggest in the continent and one of the most subsidized (获得补助的) networks in the world.

    The first trains leave the station at 5 a.m. and the last after midnight as the crowd move from the outskirts of the 20 million-strong megacity (大城市). Mexico City's Metro also attracts a sizeable group of passengers who are unwilling to spend hours in traffic jams. There is a master plan to build new lines and extend existing one, but financial constraints (约束) complicated by the fact that the system runs through different jurisdicitons (管辖权) mean progress is slow.

    As soon as a person dies, decomposition(分解) begins. And the first visitors arrive. “Within 5 to 15 minutes of death, flies or other insects begin to colonize the body.” says Rabi Musah, an organic chemist at the University at Albany.

    She says different species turn up at different stages of decomposition. “So because of that, depending upon what entomological(昆虫学的) evidence you find, you can learn something about when the person died in terms of the timing of the death.”

    Flies don't tend to stick around when disturbed by detectives. But they do leave behind eggs. The eggs are hard to tell apart by appearance alone, so specialists raise them until they hatch, a few weeks later—and they get a species ID and, with a little guesswork, a person's time of death.   But Musah has come up with a more time-saving approach: chemical analysis of the eggs. She and her team investigated that method by first harvesting flies with pig-liver traps hidden throughout New York City. They collected the trapped flies and then chemically analyzed their eggs. And it turns out each species of fly egg has a unique chemical fingerprint—enough to tell the eggs apart without raising the eggs to maturity. The study is in the journal Analytical Chemistry.

    Musah and her colleague Jennifer Rosati are now testing the method on a real case. “And once we do that we will be publishing some case studies to illustrate(阐明) that this is a method that can be used, and hopefully eventually it's something that will stand up in court, and something that could speed up detective work—or help deal with a cold case.”

    It was when I was walking to my office, trailed by three young people whose ages ranged from 16 to 25, flowing down the corridor behind me like the tail of a kite, that I thought of it for the first time.

    This could be because I am not actually a mother. Until recently, I was not a "real" stepmother either. But I have been living with the man who is now my husband, Bernardo for 10 years and in those 10 years, not only have his younger daughters spent every other weekend and half of their school holiday with us but also his son has lived with us full-time. In fact, when Bernardo asked me to move in, he asked his son for permission first.

    Being a step mum is hard enough but being a sort-of-step-mother is about the most awkward position a mature woman can find herself in. With my sort-of-steppies, I have occupied a place of influence, power and sometimes extreme anger by turns. I have stepped on a delicate path between being a grown-up friend, a bridge of influence with their father, the woman of the house, and a figure of authority – but not too much.

    Love the kids or hate them, you must always remember that no matter how much you cook, clean, hug, comfort and discipline, you will never actually count.

    To survive, I trained myself to love the stepkids as hard as I could, but not to care. It's a handy piece of good mental health trickery I recommend to anyone in my position. I can help with homework, yes, but not bother about the results of that homework. I can teach them good manners, but not care about the bad habits they learn at home. Semi-detached is the position.

Young Adult Groups

    ●Around the World in 80 Books — 9,186 members

    If you love exploring the world through books, you have come to the right place! It all started as a challenge on TNBBC in 2009, and now we have our own group! Challenge participation is not a requirement of joining. Anyone who loves reading books is welcome.

    Website: http: //www.worldinbooks.com

    Rules: Respect each other's opinions and have fun!

    ●Readers That Love Giveaways — 734 members

    This group is for readers that enjoy entering give-aways and finding freebies(免费物)! Follow us for the newestbargain, discounted, and free e-books, as well as new releases and book recommendations. Website: http://www.fireandicebooktours.com

    Rules: Please share your items in the appropriate folders!

    ●Book Loving Kiwis — 706 members

    A group for New Zealand book lovers（and authors）and lovers of New Zealand books（and books in general）. Aplace to share what we're reading, introduce books we have written, and discuss and recommend books. Please recommend us to your friends.

    Website: http://www.kiwisbook.com

    Rules: Enjoy reading! Respect all group members and their opinions.

    ●A Book and a Cappucino — 77 members

    This group is for anyone who likes to read and likes to read at their own pace. It does not matter how much or how little you read. It's just a friendly place to discuss what you're reading and to get ideas for your next read. You can participate as much or as little as you like.

    Website: http://www.bookandcappucino.com

    Rules: Be respectful to all. Everyone has a right to share opinions.

    In a recent series of experiments at the University of California, researchers studied toddlers' thinking about winners and losers, bullies (欺凌) and victims.

    In the first experiment, toddlers (学步儿童) watched a scene in which two puppets (木偶) had conflicting goals: One was crossing a stage from right to left, and the other from left to right. The puppets met in the middle and stopped. Eventually one puppet bowed down and moved aside, letting the other one pass by. Then researchers asked the toddlers which puppet they liked. The result: 20 out of 23 toddlers picked the higher-status puppet — the one that did not bow or move aside. It seems that individuals can gain status for being dominant (占优势的) and toddlers like winners better than losers.

    But then researchers had another question: Do toddlers like winners no matter how they win? So, researchers did another experiment very similar to the one described above. But this time, the conflict ended because one puppet knocked the other down and out of the way. Now when the toddlers were asked who they liked, the results were different: Only 4 out of 23 children liked the winner.

    These data suggest that children already love a winner by the age of 21-31 months. This does not necessarily mean that the preference is inborn: 21 months is enough time to learn a lot of things. But if a preference for winners is something we learn, we appear to learn it quite early.

    Even more interesting, the preference for winners is not absolute. Children in our study did not like a winner who knocked a competitor down. This suggests that already by the age of 21-31 months, children's liking for winners is balanced with other social concerns, including perhaps a general preference for nice or helpful people over aggressive ones.

    In a time when the news is full of stories of public figures who celebrate winning at all costs, these results give us much confidence. Humans understand dominance, but we also expect strong individuals to guide, protect and help others. This feels like good news.