When I was 12, all I wanted was a signet (图章) ring. They were the "in" thing and it seemed every girl except me had one. On my 13th birthday, my Mum gave me a signet ring with my initials(姓名首字母) carved into it. I was in heaven.

    What made it even more special was that it was about the only thing that wasn't being "replaced". We'd been burnt out in fires that swept through our area earlier that year and had lost everything—so most of the " new" stuff (东西) we got was really just to replace what we'd lost. But not my ring. My ring was new.

    Then, only one month later, I lost it. I took it off before bed and it was missing in the morning. I was sad and searched everywhere for it. But it seemed to have disappeared. Eventually, I gave up and stopped looking for it. And two years later, we sold the house and moved away.

    Years passed, and a couple of moves later, I was visiting my parents' when Mum told me that she had something for me. It wasn't my birthday, nor was it Easter or Christmas or any other gift-giving occasion. Mum noticed my questioning look. " You'll recognize this one," she said, smiling.

    Then she handed me a small ring box. I took it from her and opened it to find my beautiful signet ring inside. The family who had bought our house 13 years earlier had recently decided to do some redecorations, which included replacing the carpets. When they pulled the carpet up in my old bedroom, they found the ring. As it had my initials carved into it, they realized who owned the ring. They'd had it professionally cleaned up by a jeweler before sending it to my mother. And it still fits me.

    Their cheery song brightens many a winter's day. But robins are in danger of wearing themselves out by singing too much. Robins are singing all night一as well as during the day, British-based researchers say.

    David Dominoni, of Glasgow University, said that light from street lamps, takeaway signs and homes is affecting the birds' biological clocks, leading to them being wide awake when they should be asleep.

    Dr Dominoni, who is putting cameras inside nesting boxes to track sleeping patterns, said lack of sleep could put the birds' health at risk. His study shows that when robins are exposed to light at night in the lab, it leads to some genes being active at the wrong time of day. And the more birds are exposed to light, the more active they are at night.

    He told people at a conference, "There have been a couple of studies suggesting they are increasing their song output at night and during the day they are still singing. Singing is a costly behaviour and it takes energy. So by increasing their song output, there might be some costs of energy."

    And it is not just robins that are being kept awake by artificial light. Blackbirds and seagulls are also being more nocturnal. Dr Dominoni said, "In Glasgow where I live, gulls are a serious problem. I have people coming to me saying `You are the bird expert. Can you help us kill these gulls?'.During the breeding(繁殖)season, between April and June, they are very active at night and very noisy and people can't sleep."

    Although Dr Dominoni has only studied light pollution, other research concluded that robins living in noisy cities have started to sing at night to make themselves heard over loud noise.

    However, some birds thrive(兴旺)in noisy environments. A study from California Polytechnic University found more hummingbirds in areas with heavy industrial machinery. It is thought that they are capitalising on their predators(天敌)fleeing to quieter areas.

    Recently, people in US education have gotten extremely worried because a new report has shown that American students have a math problem.

    The 2015 Program for International Student Assessment(评估)(PISA) shows math scores in the US getting lower and no improvement in science or reading. PISA tests 15-year-olds from different countries and regions in their math, science and reading skills. About 540, 000 students from 72 countries and regions took part in the assessment in 2015.

    US scores in reading and science were about the same as three years ago, leaving Americans near the middle of the bigger group. But the situation in math is much more worrying. The US average score was 470, below the OECD(经合组织)test average of 490, meaning the US was No. 40 among the 72 countries and areas. It was 12 points lower than in 2012 and 18 points lower than in 2009. So, what is going on with American students' math skills?

    One reason may be that the US does not teach math in enough depth. "Students are often good at answering the first part of a problem in the United States, "said Andreas Schleicher, director of education and skills at OECD. "But as soon as students have to go deeper and answer the more complicated part of a problem, they have difficulties. "In comparison, many high-performing countries and regions in math teach a lot less but focus in much greater depth,  especially when you look at East Asia, Japan and Singapore, according to Schleicher.

    Another reason may be the fact that many people in the US are unwilling to travel to foreign countries to learn better teaching practices. "One of our biggest challenges in the US is that the teachers are not going out and seeing what high-performing countries do differently, "said Wendy Kopp, who started Teach for America, in a news program.

    Customers who come into the Waffle House recognize server Evoni Williams, a soft-spoken 18-year-old from Texas City. It all started with a Facebook post. On the morning of March 3, Laura Wolf was eating breakfast at the Waffle House in La Marque when she overheard an older man, who reminded her of her late father, tell Williams he had trouble with his hands. The man, later identified as regular customer Adrien Charpentier, had an oxygen tank nearby and needed help cutting up his food. “Without hesitation,” Wolf wrote, Williams “took his plate and began cutting up his ham.”

    Impressed, Wolf posted the moment on her Facebook page to share the warmth and kindness with all. The following day, Williams's Facebook notification（关注）began to light up. Her friends saw Wolf's post and tracked her in it.

    Williams had no idea that someone took a photo that morning. The diner was so busy that a line extended outside the door. She said helping Charpentier was reflexive. She has been working at Waffle House since last June to save for college, and this, she figured, was just the right thing to do. “I would want someone to help my grandmother or grandfather,” Williams said.

    The post began to make its rounds in La Marque and eventually landed in front of the city's mayor, Bobby Hocking. He decided to declare March 8 as Williams's day, and also received an email from Texas Southern University President Austin A.Lane, asking if the school could present Williams with a scholarship.

    Williams still works at Waffle House five days a week and plans to do so until she starts classes in the fall at Houston-based Texas Southern. Wolf said Williams does not have a car to get to classes, but some people have offered to start a GoFundMe page for her, proving that a moment of a kindness can change a life.

    Say you're in the supermarket parking lot，holding your baby，bags of goods，and trying to open your car. A stranger walks up and says，" Here，let me hold your baby." Should you let him?

    According to a new New York University study，knowing whether or not to trust someone is so important that we can tell whether a face is trustworthy before we even consciously know it's there. The researchers knew from previous studies that people are fairly similar when it comes to how they judge a face's trustworthiness. They wanted to find out whether that would be true if people only saw a face for a quick moment—an amount of time so short that it would prevent making a conscious judgment.

    To carry out their study，the researchers monitored the amygdala (扁桃腺结构) of 37 volunteers while showing them 300 faces for 33 milliseconds each. Those faces had already been tested with a different set of 10 subjects，who saw them for much longer. In those earlier tests，people agreed about whether to trust each face. In this new study，fascinatingly，different parts of the amygdala lit up when a subject saw an untrustworthy face and a trustworthy one—and it lit up more when the face in question was suspicious (可疑的).

    " Faces that appear likely to cause harm are suddenly tracked by the amygdala，so it could then quickly change other brain processes and make fast responses to people—approach or avoid，" says Jon Freeman，the study's senior author. "Our talents for making instant judgments could either come from birth or be learned from the social environment."

    So should you trust the guy in the parking lot? Your brain already knows.

    Did anyone find the names of "Great Britain", "the United Kingdom", "England" and "the British commonwealth" which have the same meaning? Strictly speaking, these names all refer to something different. None of them are exactly the same as any of the others.

    The British isles refer to the main islands and several thousand small ones as well, which you can see on the map. Great Britain, or Britain, refers to the larger of the two main islands. But the word "Britain" is often used as a short form for the United Kingdom or you call it the UK.

    Now as for England, it refers simply to the largest of the three countries on the island of Great Britain. The United Kingdom is the name of the state and the official name of the country, which many people popularly refer to England.

    Finally, the Britain commonwealth is the usual name for what is left of the British Empire. This change shows the weakening of British Empire and the rising of the national liberation movements throughout the world today.