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    Adding math talk to story time at home is a winning factor for children's math achievement, according to a new research from a university. The study from psychologists Sian Beilock and Susan Levine shows a marked increase in math achievement among children whose families used Bedtime Math, an iPad app that delivers engaging math story problems for parents and children to solve together.

    Even children who used the app with their parents as little as once a week saw gains in math achievement by the end of the school year. The app's effect was especially strong for children whose parents tend to be anxious or uncomfortable with math.

    Previous research from this group has demonstrated the importance of adults' attitudes about math for children's math success. For example, a recent study found that math-anxious parents who help their children with math homework actually weaken their children's math achievement.

    The new findings demonstrate that structured, positive interactions around math at home can cut the link between parents' uneasiness about math and children's low math achievement.

     “Many people experience high levels of anxiety when they have to solve a math problem, with a majority of adults feeling at least some worries about math,” said Beilock, professor in Psychology and author of Choke, a book about stress and performance. “These math-anxious parents are probably less likely to talk about math at home, which affects how competent their children are in math. Bedtime Math encourages a dialogue between parents and kids about math, and offers a way to engage in high-quality math interactions in a low-effort, high-impact way.”

    Study participants included 587 first-grade students and their parents. Families were given an iPad installed with a version of the Bedtime Math app, with which parents and their children read stories and answer questions involving math, including topics like counting, shapes and problem-solving. A control group received a reading app that had similar stories without the math content and questions related to reading comprehension instead. Children's math achievement was assessed at the beginning and end of the school year. Parents completed a questionnaire about their nervousness with math.

    The more times parents and children in the math group used the app, the higher children's achievement on a math assessment at the end of the school year. Indeed, children who frequently used the math app with their parents outperformed similar students in the reading group in math achievement at year's end.

    I've been researching my family tree since 1998 ，and I've long been curious about DNA as a way to learn more about my roots. The technology has come a long way in the last decade, and it's become more affordable too. Finally, I went ahead and ordered a Y-DNA test.

    The results came in my email inbox from the DNA lab! When I logged in to see the results, there are 29 living people today with whom I share a common direct male ancestor in about the last 1,000 years. They live in Ireland, England, Scotland, South Africa, the United States and probably elsewhere.

    I had two close matches, and the rest were more distant. They both live in Ireland! What makes the connection  to these two men so interesting is that most Irish genealogical (族谱的)records were burned in fires in Dublin and don't exist today. Without them, it's hard to trace Irish roots any further back than the 1800s. I've written emails to both of them and hope to hear back!

    I did some more research on my Y-DNA and found my direct male ancestors were Celtics. They seem to have lived in Western Europe at the time of Ancient Rome. Migration patterns show that my DNA group likely originated in Western Asia, living there 20, 000 and 30, 000 years ago. There are relatives with similar DNA going thousands of years back in what is now Iran, India, Syria, Israel and Turkey.

    I was so excited by these results that I decided to trace my motherly line too. My DNA is already at the lab, so now I just have to wait another month or so, and I'm sure to find more interesting things.

    About three decades ago, China was known as the “Bicycle Kingdom”. But later on, bikes were replaced by their fuel-powered competitors.

    But recent months have seen a recovery of the humble bike across China, with an increasing number of people choosing cycling instead of driving to schools, to workplaces or to do sightseeing. The introduction of bike-sharing schemes, pioneered by start-ups like Ofo and Mobike, has brought the trend to a new level.

    People can unlock the shared bikes by simply using their smart phone. The bikes are equipped with GPS and can be left anywhere in public for the next user. They're popular among many Chinese people as they provide an effective solution to the “last mile” problem, which refers to the final leg of a person's journey.

    “In places where the subway doesn't extend, where it's difficult to change from one kind of transport to another, it's so easy to get where you want to go with Mobike,” Hu Hong. 29, told AFP. She pedals（骑车）to her Shanghai real-estate job.

    However, the schemes have also led to problems such as illegal parking, vandalism（故意毁坏）and theft. Last month, two nurses in Beijing were placed under administrative punishment for five days for putting locks on two shared bikes. And in December, a man who stole a shared bike was sentenced to a 3-month detention（拘留）, and fined 1,000 yuan by the Shanghai Minhang People's Court.

    “Bike-sharing is a greener method of transportation and provides a user-friendly experience.” said Liu Xiaoming, vice-minister of transport.

    “But it's a combination of online and offline business. Operators are usually strong in online services, but lack offline business experience, which causes problems.”

    Passenger pigeons (旅鸽) once flew over much of the United States in unbelievable numbers. Written accounts from the 18th and 19th centuries described flocks (群) so large that they darkened the sky for hours.

    It was calculated that when its population reached its highest point, there were more than 3 billion passenger pigeons—a number equal to 24 to 40 percent of the total bird population in the United States, making it perhaps the most abundant bird in the world. Even as late as 1870 when their numbers had already become smaller, a flock believed to be 1 mile wide and 320 miles (about 515 kilometers) long was seen near Cincinnati.

    Sadly the abundance of passenger pigeons may have been their undoing. Where the birds were most abundant, people believed there was an ever-lasting supply and killed them by the thousands.

    Commercial hunters attracted them to small clearings with grain waited until pigeons had settled to feed, then threw large nets over them, taking hundreds at a time. The birds were shipped to large cities and sold in restaurants.

    By the closing decades of the 19th century, the hardwood forests where passenger pigeons nested had been damaged by American's need for wood, which scattered (驱散) the flocks and forced the birds to go farther north, where cold temperatures and storms contributed to their decline. Soon the great flocks were gone, never to be seen again.

    In 1897, the state of Michigan passed a law prohibiting the killing of passenger pigeons but by then, no sizable flocks had been seen in the state for 10 years. The last confirmed wild pigeon in the United States was shot by a boy in Pike County, Ohio, in 1900. For a time, a few birds survived under human care. The last of them, known affectionately as Martha, died at the Cincinnati Zoological Garden on September 1, 1914.

 "BANG!" I pulled the door heavily behind me. "Never set foot in this house again!" stormed father. I rushed out of the flat and ran along the street.

A young man who held a child in his arms walked past me. I felt as if I saw my childhood from another space: happy and carefree. But now...I don't know whether it is because I have grown up or because Dad is getting old. We differ in our ways of thinking. We are just like two people coming from two different worlds. It feels like there is an iron(铁制的) door between us that can never be opened.

I wandered in the streets, until I had only the street lights to keep me company. My heart was frozen on this hot summer night. When I finally reached the high-rise apartment block in which I lived, I saw that the light was still on.

I thought to myself, "Is Father waiting for his boy, or still angry with him?"

All the lights were off except Father's.

Dad was always like this. Maybe he didn't know how to express himself. After an argument he had the habit of tucking me underneath the covers(掖被子) while I was sleeping. This was how he always was. He had been a leader for so long that telling everyone else what to do had become his second nature.

The light was still on.

"Am I wrong?" I whispered, maybe... With the key in hand, I was as nervous as I had ever been. At last, I decided to open the door. As soon as I opened the door, tears ran down my cheeks. I suddenly realized that the iron door that I had imagined between us did not exist at all. Love——it's second to none.