A biologist from the National Park Service discovered a rare and unusual mammoth(猛犸) skull(颅骨) buried in a 13,000-year-old rock layer on the Santa Rosa Island, the second largest landmass in the Channel Islands, California. The fossil of the extinct giant animal is leaving many paleontologists(古生物学家) scratching their heads. Despite the fact that it's possibly the best preserved mammoth skull ever found and of high scientific importance, the species of the individual it belonged to can't seem to be identified yet—it's too big to be a pygmy(特别矮小的) mammoth and too small to have come from a Columbian mammoth. Some say it's a new species while others believe the truth lies somewhere in between.

    The first mammoths showed up in North America around two million years ago, but it was only during the last two ice ages that the Columbian species, which could grow to be up to 14 feet tall, made its way to the Channel Islands 100 miles west of Los Angeles. Once the ice melted, many populations became trapped on the island and evolved into pygmy mammoths, an endemic species(地方种) to the Channel Islands which grew only to six feet tall.

    Judging from its size, the newly found mammoth skull doesn't seem to fit any of the two species, Columbian or pygmy. To make things even more confusing, one of its two tusks(象牙) is nearly five feet long and coiled in a manner that resembles those of fully grown mammoths but the left tusk is shorter and sloped, more like a juvenile(青少年).

    This has caused some scientists to say the Santa Rose skull may belong to a transitional species. Whatever's the case, a following examination of the mammoth's teeth should put the matter to rest. The analysis will also tell us how old the mammoth was when it died, so we can tell for sure whether it was an adult or juvenile.

    More interesting than the mammoth's lineage, however, might be its story. The giant mammal lived 13,000 years ago or roughly the same timeline of the “Arlington Man”, a 13,000-year-old human skeleton also found on Santa Rosa. Some 3,000 years later humans were already spread throughout the continent and the Channel Islands' mammoth went extinct. The present finding might help reveal a link between the two.

    The remains also seem to confirm a long-held assumption that there were two mammoth migrations to the Channel Islands. “The discovery of this mammoth skull increases the probability that there were at least two migrations of Columbian mammoths to the island: during the most recent ice age 10,000 to 30,000 years ago, as well as the previous ice age that occurred about 150,000 years ago,” said USGS geologist Dan Muhs.

    The Indian government may use 3D paintings as virtual (虚拟的) speed-breakers on major highways and roads, in an attempt to check speeding and careless driving, and eventually make its deadly roads a little safer. “We are trying out 3D paintings used as virtual speed breakers to avoid unnecessary requirements of speed breakers (减速带),” India's transport minister Nitin Gadkari tweeted.

    The visual illusions (幻象) are supposed to encourage drivers to slow down automatically. Earlier this month, India bad ordered the removal of all speed breakers from highways, which are considered to be a danger to safety for high-speed vehicles.

    India has the highest number of road accident deaths in the world According to the World Health Organization, over 200,00 people are killed by road accidents due to poor application of road safety laws. This is considerably higher than its official figures of 141,526 for 2014.

    The use of visual illusions as speed breakers was first pioneered in the American city of Philadelphia in 2008, as part of a campaign against speeding motorist. The technique has also been tried out in China to create floating 3D crossings.

    India, cities such as Ahmadabad and Chennai have already experimented with 3D zebra crossings in the last one year. In Ahmadabad for instance, two artists, mother and daughter have painted 3D crosswalks in the first few months of this year. The artists say their motto is “to increase the attention of drivers”, and that the concept has been successfully tested in zones where accidents easily occur on a highway.

    However, critics argue that once divers know that these speed briers are visual illusions, they may ignore them. Others also point out that India's decision does not consider the safety of a large walkers. In the end, the new policy may be just one step towards improving road safety.

    Dyeing eggs has long been an Easter tradition, but it's the dyeing of baby chicks that is upsetting in some states.

    The dye, which is often ordinary food coloring, is either injected into eggs being hatched or sprayed onto newly hatched chicks. Although hatchery owners say the practice is harmless, critics argue that spraying the birds with color is stressful and that dyeing the animals transforms them into something attractive that can be thrown away when their colorful feathers disappear.

    “These are living creature and dyeing them sends out a message saying that they are more of a new and unusual object than a living animal,” said Dr. Marc Copper, senior scientific manager for the Royal Society for the Prevention of Cruelty to Animals.

Dyed chicks — and sometimes rabbits — have been a traditional part of the Easter holiday in some parts of the world, but the practice has gone largely underground in the U.S. because many people view it as cruel.

    Today, about half of U.S. states ban the dyeing of animals, but last month the Florida Legislature passed a bill to remove the state's 45-year-old ban. The drive to end the law wasn't related to Easter chicks; it was done at the request of a dog groomer(美容师) who wanted to enter pet beauty contests.

    Florida governor Rick Scott must agree to remove the ban, which would be lifted July 1, but the Animal Rights Foundation of Florida(ARFF) has asked him not to remove the ban. In addition to allowing animals dyeing, the law would also lift a ban on selling baby animals as pets, and the organization fears that next year the state could see hundreds of dyed baby chicks on the market.

As long as the dye is not poisonous, experts say the birds' health isn't affected, and there are scientific reasons to dye animals. Wildlife researchers often inject eggs with dye to track birds in the wild, and teachers have dyed chicks for educational purposes. However, animal advocates are quick to point out that dyeing baby chicks for Easter isn't educational — it's done simply to earn profits.

    My grandmother often said to me, "You can count the number of your true friends on the fingers of one hand." For a long time I thought this was true. However, I've now discovered my grandmother was only half right. Maybe we do only make a few "best" friends in our lifetime, but those aren't the only people that we can call friends. There are many different types. Let me tell you about a few of them.

    One type of friends is the type I call the "football mom friends". My neighbour Sally is a good example. We both have kids who play football in a football club, and someone has to take them to practise and pick them up. Sally and I and two other mothers do this. We meet sometimes and have tea and talk about what our kids are doing, but those are the only times that we meet each other. I enjoy being with these women, but we don't do anything else together.

    Another type is called the "hobby friend". That's the person you share an interest or a hobby with. Michael and Cater, who are brothers, are a good example of this type. We're all in a bird watching club. Every few weekends the members of the club go on a trip to watch different kinds of birds. There's nothing romantic about my relationship with Michael and Cater, of course. We just share interest in birds.

    Then there's the "other half the couple" type of friends. Jim is married to Rose, a friend that I have known since college. When Rose married Jim, I realized that I would have to be Jim's friend if I want to continue to be Rose's. Jim and I don't share so many interests, but we do have a friendly relationship.

    I'm not so sure I like my friends any more. I used to like them — to be honest. We'd have lunch, talk on the phone or exchange e-mails, and they all seemed normal enough. But then came Facebook and I was introduced to a sad fact: many of my friends have dark sides that they had kept from me.

    Today my friends show off the more unpleasant aspects of their personalities via Facebook. No longer hidden, they're thrown in my face like TV commercials — unavoidable and endless advertisements for the worst of their personalities.

    Take Fred. If you were to have lunch with him, you'd find him warm, and down-to-earth. Read his Facebook and you realize he's an unbearable, food-obsessed bore. He'd pause to have a cup of coffee on his way to save a drowning man — and then write about it.

    Take Andy. You won't find a smarter CEO anywhere, but now he's a CEO without a company to lull. So he plays Mafia Wars on Facebook. He's doing well — level 731. Thanks to Facebook, I know he's playing about 18 hours a day. Andy, you've run four companies — and this is how you spend your downtime(业余时间)? What happened to golf? What happened to getting another job?

    Take Liz. She is positive that the H1N1 vaccine(甲流疫苗) will kill us all and that we should avoid it. And then comes Chris who likes to post at least 20 times a day on every website he can find, so I get to read his thoughts twice, once on Facebook and once on Twitter.

    In real life, I don't see these sides of people. Face to face, my friends show me their best. They're nice, smart people. But face to Facebook, my friends are like a blind date which goes horribly wrong.

    I'm left with a dilemma. Who is my real friend? Is it the Liz I have lunch with or the anti-vaccine lunatic(狂人)on Facebook? Is it the Fred I can grab a sandwich with or the Fred who weeps if he's at a party and the wine isn't up to his standards?

    Language learning apps are very popular now and offer opportunities to learn vocabulary and practice grammar. But there has been a discussion about just how effective such apps can be.

    Among the most popular apps are Duolingo and Busuu. A previous research found positive results on the use of them. But it mainly concentrates on studies with learners who had signed up for language courses and these apps worked as an after-class support, so the results were not always reliable. A recent study of 4,095 Busuu users has been carried out to find out if users can actually learn a language with an app.

    Busuu provides learning materials for 12 different languages. It offers special models where some contents are available for free while some contents are not, We find that its users are an even mix of men and women. More than half consider themselves to be at the beginner level as there is a decrease in users as their language levels go up. Most people use the app because of personal interest, or because they want to study or live abroad. Females tend to use it less often but for longer periods of time than male users.

    Getting any feedback on Busuu depends on whether your answer is correct or not. While it is helpful, this is not the sort of feedback language teachers prefer, as it does not explain why the answer is right or wrong. In spite of this, feedback in the app is very highly rated.

    More than 92% of the people state that the app has met their expectations and 86% consider the app as very good or good. In fact, more than 80% of the users surveyed strongly agree that using the app has helped them improve their knowledge of the language they are learning.

    Besides, language learning apps also create an environment where mistakes are only known to the users, and this can address the performance anxiety that many learners suffer from when asked to speak a foreign language. So language teachers should encourage their students to use them to do the grammar work, leaving precious class time for more language communication.