The mobile phone has become a problem for high schools. Some high-school students in Australia are not allowed to carry mobile phones during school hours.

    The mobile phone used among children has become a problem for the school years. Several children have got mobile phones as Christmas presents, and more students want them. Marry Brown, a headmaster, said that the mobile phone was a distraction to students during school hours and it also gave teachers so much trouble in their classrooms. Teachers also say that sometimes students might use phone messages to cheat during exams.

    She said some schools had tried to ban mobile phones.  Some parents felt unhappy because they couldn't get in touch with their children.

    Many teachers said students should not have mobile phones at school, if there was a good reason, they could leave their phones at school office. They also said phones were easily lost and were a distraction for studies.

    Many people say that they understand why parents would want their children to have phones, but they think schools should let students know when they can use their mobile phones.

    It was a simple letter asking for a place to study at Scotland's oldest university which helped start a revolution in higher education. A 140-year-old letter written by a lady calling for her to be allowed to study medicine at St Andrews University has been discovered by researchers. Written by Sophia Jex-Blake in 1873, the seven-page document, which urged the university to allow women to study medicine at the institution, was released yesterday on International Women's Day.

    The document was discovered buried in the university archives (档案) by part-time history student Lis Smith, who is completing her PhD at St Andrews Institute of Scottish Historical Research. She said: “We knew that Sophia Jex-Blake and her supporters, in their effort to open up university medical education for women, had written to the Senatus Academicus (校评议委员会) at St Andrews in an attempt to gain permission to attend classes there, but we didn't know documentary evidence existed. While searching the archives for information about the university's higher certificate for women, I was astonished to come across what must be the very letter Jex-Blake wrote.”

    In the letter, Sophia and her supporters offered to hire teachers or build suitable buildings for a medical school and to arrange for lectures to be delivered in the subjects not already covered at St Andrews. Although her letter was not successful, it eventually led to the establishment of the Ladies Literate in Arts at St Andrews, a distance-learning degree for women. The qualification, which ran from 1877 until the 1930s, gave women access to university education in the days before they were admitted as students. It was so popular that it survived long after women were admitted as full students to St Andrews in 1892.

    Ms Jex-Blake went on to help establish the London School of Medicine for Women in 1874. She was accepted by the University of Berne, where she was awarded a medical degree in January 1877. Eventually, she moved back to Edinburgh and opened her own practice.

    Imagine you're standing in line to buy a snack at a store. You step up to the counter and the cashier scans your food. Next, you have to pay. but instead of scanning a QR Code（二维码）with your smart phone, you just hold out your hand so the cashier can scan your fingerprint. Or, a camera scans your face, your eyes or even your ear.

    Now, this type of technology might not be far away. As technology companies move away from the traditional password, biometric（生物特征识别的）security, which includes fingerprint, face and voice ID, is becoming increasingly popular.

    In 2013, Apple introduced the iPhone 5s, one of the first smart phones with a fingerprint scanner. Since then, using one's fingerprint to unlock a phone and make mobile payments has become commonplace, bringing convenience to our lives. And since 2016, Samsung has featured eye-scanning technology in its top smart phones, while Apple's new iphone X can even scan a user's face. But despite its popularity, experts warn that biometrics might not be as secure as we imagine. “Biometrics is ideally good in practice, not so much,” said John Michener, a biometrics expert.

    When introducing the new iPhone's face ID feature, Phil Schiller, Apple's senior vice-president, said. “The chance that a random person in the population could look at your iPhones X and unlock it with their face is about one in a million.” But it's already been done. In a video posted on a community website Reddit, two brothers showed how they were each able to unlock the same iPhone X using their own face. And they aren't even twins.

    “We may expect too much from biometrics,” Anil Jain, a computer science professor at Michigan State University, told CBS News. “No security systems are perfect.”

    Earlier last year, Jain found a way to trick biometric security. Using a printed copy of a thumbprint, she was able to unlock a dead person's smart phone for the police, according to a tech website Splinter. “It's good to see biometrics being used more,” Jain told CBS News, “because it adds another factor for security. But using multiple security measures is the best defense.”

    When you get a cut, you cover it with a bandage. How do you know when to change it? Maybe you just wait until it's wet or dirty. But when people have long-term or chronic (慢性的)wounds that take months to get better, changing bandages too early or to late could make healing take even longer. Changing the dressing on a wound too often can provide an opportunity for infections to get in. But if a bandage gets very wet very quickly from the inside, it might be filling with pus (脓)--a sign an infection has begun. Judging just when to change is important.

    Chronic wounds are common in people who are older or who have certain health conditions. Chronic wounds affect around 6.5 million people per year in the United States. When Anushka Naiknaware, 13, learned about chronic wounds, she decided to make a device that could alert a person when it's time to change their bandages.

    After a lot of trials and errors, the teen settled on a design that used an “ink” filled with carbon nanoparticles(纳米粒子). The teen loaded her ink into a printer cartridge (墨盒) to print onto her special paper, which was to be made into bandage. Well, actually, Anushka loaded her ink into many, many printer cartridges. Just changing a printer cartridge isn't easy, and filling one is even harder.

    The small printed papers cost only 5 to 10 cents, Anushka estimates. The Bluetooth sensor is more expensive, but the teen notes that it could be used over and over again. She also knows there is a long way to go before her design can help patients. It hasn't been tested on a real person yet. “You have to make sure everything works perfectly,” she says.

    Snorkelling in Silfra

The clear water at this UNESCO world heritage(遗产) site in Thingvellir National Park will leave you speechless. It is one of the highest rated dive sites in the world. During this journey, you will snorkel within a crack between the Eurasian and American continents. You'll experience truly amazing views of the colorful underwater landscape, marine life(海洋生物), and geological formations. Silfra's water is fresh and drinkable at around 2℃ - 4℃ all year round. Visibility can reach more than 100 meters, and swimming often feels more like flying.

    This trip is for anyone who knows how to swim and is up for a unique adventure. We offer transportation with a pick-up in Reykjavik, and provide you with a dry suit. The total length of the tour is approximately five hours, and includes in-water snorkelling lasting around 30 minutes. We'll guide you through the main Silfra Big Crack, Silfra Hall, Silfra Cathedral and Silfra Lagoon.

Included:

    All necessary snorkeling equipment;

    Hot drinks and food;

    Silfra entrance fee of 1,000 ISK.

    Availability: All year at 09:00 and 15:00. Pick-up in one hour before.

    Requirements:

    Participants need to complete the Silfra medical statement before the tour.

    Divers must:

    Be at least 18 years old (young people under 18 years old need a signature from their legal guardian), and the maximum age is 65 years old;

    Be able to communicate in English.

    Be physically fit;

    Not be pregnant;

    Not be under the influence of alcohol or drugs;

    Sign a medical form.

    People have understood that kindness is good for the person who receives help. For example, when we give food to a hungry person, he is blessed. However, scientists have recently begun to study the effect kindness has on the person giving it. What they have found is that doing good is good for the doer. Acts of kindness can improve health, help a person reach goals and even add years to a person's life.

    The first study to show the connection between doing good and living a long life was a study on aging. Beginning in 1956, scientists studied a group of married mothers for 30 years. They thought the women with the most children would die first. But the number of children a woman had did not matter. Wealth did not matter. Education did not matter. What did matter was whether they volunteered. Women that volunteered had fewer diseases during their life.

    Many other studies have found the same positive effects. Helping other people improves long-term health. The gains are the same for men, women, old people and the young. Those who volunteered had fewer serious diseases than those who did not volunteer. This included diseases such as heart attack, cancer and stroke.

    Scientists are researching many possible causes. One possible cause is an increase in antibodies （抗体）, which help fight against disease. One study showed the body produces more antibodies after an act of kindness. This increase in antibodies can last nearly an hour after one act of kindness is finished.

    Another one is an increase in a chemical that fights the effects of stress from life. Scientists have found a link between being kind to people and an increase in the chemical oxytocin. Oxytocin is a chemical produced in the brain. It reduces many of the harmful chemicals the body produces under stress.