Computers have beaten human world champions at chess and, earlier this year, the board game Go. So far, though, they have struggled at the card table. So we challenged one AI to a game.

    Why is poker(扑克) so difficult? Chess and Go are “information complete” games where all players can see all the relevant information. In poker, other players' cards are hidden, making it an “information incomplete” game. Players have to guess opponents' hands from their actions—tricky for computers. Poker has become a new benchmark for AI research. Solving poker could lead to many breakthroughs, from cyber security to driverless cars.

    Scientists believe it is only a matter of time before AI once again vanquishes humans, hence our human-machine match comes up in a game of Texas Hold's Em Limit Poker. The AI was developed by Johannes Heinrich, researcher studying machine learning at UCL. It combines two techniques: neural(神经的) networks and reinforcement learning(强化学习).

    Neural networks, to some degree, copy the structure of human brains: their processors are highly interconnected and work at the same time to solve problems. They are good at spotting patterns in huge amounts of data. Reinforcement learning is when a machine, given a task, carries it out, learning from mistakes it makes. In this case, it means playing poker against itself billions of times to get better.

    Mr Heinrich told Sky News: “Today we are presenting a new procedure that has learned in a different way, more similar to how humans learn. In particular, it is able to learn abstract patterns, represented by its neural network, which allow it to deal with new and unseen situations.”

    After two hours of quite defensive play, from the computer at least, we called it a draw.

    Mrs. Blake teaches English in a large school in the inner area of a big city on the west of coast. Even since she was a young girl, she has wanted to become a teacher. She has taught eight years now and hasn't changed her mind. After she graduated from high school， she went on to college. Four years later，she received her bachelor's degree （B A） in English and her teaching certificate（证书）. Then she went to teach in the secondary schools of her state. In the summers，Mrs. Blake takes more classes； she hopes to get a master's degree （M A）. With an MA，she will receive a higher salary and if possible， she hopes to get a doctor's degree as well. The school day at Mrs. Blake's high school，like that in many high schools in the United States，is divided into one hour each. Mrs. Blake must teach five of these periods. During her free period，which for her is from 2 to 3 P.M. ，Mrs. Blake must meet with parents，make out examinations，check assignments at all，Mrs. Blake works continuously from the time she arrives at school in the morning till the time she leaves for home late in the afternoon.

    We all love bank holidays. In the UK, we only get eight bank holidays in one year, and at least five of those occur around Christmas time and Easter time! A bank holiday is a British English term. This is an official day that is decided by the government, when banks, shops and offices close for the day even though it's a weekday—usually a Monday, and a lot of people have a day off work.

    Bank holidays are different in Colombia—firstly, they are called “festivos”. There are twenty festivos for the whole country in one year! In Britain ，people get more holiday allowance(津贴)than Colombians but fewer bank holidays. There can be even more festivos in Colombia, depending on which region of Colombia you live in. This is because different regions have their own holidays. For example, some regions have a patron saint(守护神) in their region, so they have an extra festivo to celebrate that saint.

    However, there are some days that are national holidays for historical reasons. There is an Independence Day celebration on July 20 every year. This is just like Bastille Day in France on July 14, or Independence Day in the United States on July 4. Other important festivos in Colombia are :Labour Day, on May 1, and Columbus Day on October 12. Columbus Day is a historical bank holiday that almost every county on the continent of America celebrates. This includes Colombia, Chile, Peru, Argentina, Mexico and the United States. It is a memorialization of the day that the Italian sailor, Christopher Columbus, first reached land on the continent in the year 1492. Many people criticize this day and say it is not something to celebrate because of the way Columbus and his teams treated the people that were already living there.

    Regardless of how far we'd like to believe gender(性别) equality in the workplace has come, there's still a yawning gap between male and female leaders in the professional world. A 2018 statistic shows that women nowadays hold just 5.8 percent of CEOs positions at S&P 500 companies, according to Catalyst.

    While it's not a huge shock that women are somewhat underrepresented in leadership positions, what is surprising though, is the fact that females may actually be better suited to lead in almost every area, at least according to new findings from the BI Norwegian Business School.

    In their research，Professor yvind L. Martinsen and Professor Lars Glas surveyed (调查)2,900 managers with a special focus on personality types. The results were clear: Women scored higher than men in four of the five major leadership-centric categories.

    While some people believe that men inherently make better leaders — probably because they picture a leader with a commanding voice, which is more typical of men than women — this piece of research suggests that women are better at methodical management and goal-setting, openness, sociability and supportiveness, as well as ability to communicate clearly.

    There was one area in which men scored higher than women, though, and that was on emotional stability and ability to face job-related pressure and stress. The results suggest that women are more sensitive to the effects of high-pressure or highly emotional situations.

    Obviously，it's important to consider individual(个人的) differences. Anyone, regardless of gender, may be an inspiring leader and a competent boss. But next time you're hiring for a management position, you just might want to give the resumes(简历) from female candidates a harder look.

    Exercise is known to benefit people's mental health, but scientists recently discovered that too much exercise may have a negative effect on it.

    The researchers studied about 1.2 million people in the United States in 2013, 2015 and 2017. The participants, on average, experienced 3, 4 days of poor mental health each month. Those who did exercise experienced 1, 5 fewer days of poor mental health per month, compared to those who didn't exercise at all. The team found that people who exercised for 30 to 60 minutes three to five times a week had the best mental health, but those who exercised for more than three hours had worse mental health than those who didn't exercise at all.

    The scientists think that people who exercise so much may experience poorer mental health because that much exercise can be a sign of obsessive (强迫症患者) behaviors that have been associated with poor emotional and psychological outcomes. However, the only mental health disorder that the researchers looked at was depression.

    Among those who had been diagnosed with depression, people who did exercise experienced 3.75 fewer negative mental health days than those who did not, showing an ever greater difference, According to the Centers for Disease Control and Prevention. 7, 6 percent of people in the U.S. age 12 and over have depression. While all types of exercise appeared to help with mental health, cycling, gym-based exercise and team sports were the most beneficial.

    The team also looked at more specific factors, like education. People with a college education reported 17.8 percent fewer days of poor mental health than those without that level education Additionally, people in a healthy BMI (体重指数) range reported a 4 percent reduction in poor mental health days thin those whose BMIs were high. Even salary was a factor: compared to people with bower salaries, those with higher salaries experienced a 17 percent reduction in poor mental health days.

    The study showed that exercise can help with mental health, but that in some cases, limiting it may be necessary.

Dear Students,

    I am delighted to be your guest.

    I would like to tell you about myself. I have been a news reporter for the past fifteen years. I chose this job so I could travel the world, but the job has taught me many unforgettable lessons. The work is sometimes difficult. I have seen famines, wars, earthquakes, poverty and death. But I have also seen courage, hope and happiness.

    In India, I visited a city where there were many homeless children. Some were as young as four years old. They lived in the streets and survived by begging or stealing. But then a wonderful lady called Rosa opened a home for them. Within one year, she was looking after two hundred children. She clothed them, fed them, and taught them. She gave them hope.

    Another time, I was in Turkey after a terrible earthquake, in one place. I found an old lady whose house was in ruins, her son was missing and rescuer workers said there was no chance that he was still alive. But the old lady did not give up hope. For four days, she moved heavy stones one at a time by herself. She did not stop until she found her son. He was alive.

    Here in China, I met a young boy with a serious condition. He had undergone twenty operations and spent nearly his whole life in hospital. I thought he would be sad, but when I met him, his smile was so warm and welcoming.

    In life, we need role models that we can admire and learn from. When my life is difficult, I try to remember the courage and goodness of these three people.