Clara Barton，founder of the American Red Cross，gained worldwide honor for her dedication to easing human suffering and earned the nickname  “Angel of the Battlefield.”

    Barton was born into a liberal (开明的) freethinking family in 1821. Her elder brothers and sisters happily tutored her in math and reading, so when she entered school at three years old, she could read and spell three-syllable words. {#blank#}1{#/blank#}

    Concerned about Barton's difficulty in making friends, her parents sent her to a boarding school, hoping it would make her more comfortable with her peers. {#blank#}2{#/blank#} Barton lost her appetite and cried constantly. After only one term, she had to be brought home. Then, Barton stayed out of school to nurse her older brother through a serious injury and also volunteered to care for poor families during a smallpox (天花）outbreak.

    In 1861，the Civil War broke out. The sight of wounded soldiers touched Barton deeply. She began to collect and distribute food, bandages, medicines, and other supplies for the Union army.

    {#blank#}3{#/blank#} There, with little concern for her own safety, she cooked meals, assisted surgeons, and comforted wounded soldiers.

    Eventually，because of working too hard，Barton collapsed，ill with typhoid fever (伤寒症). {#blank#}4{#/blank#} It was there that she learned of an organization based in Switzerland — called the International Red Cross, whose work mirrored her own.

    Shortly after Barton arrived back home in 1873，her sister died. {#blank#}5{#/blank#} When recuperating (休养）at a health facility in New York，she began planning for the establishment of an American wing of the International Red Cross. Although at first the government resisted，her efforts finally paid off. The American Red Cross was officially organized on May 21, 1881. Her influence lives on today in the work of the organization she founded.

    In 2017, AlphaGo defeated Chinese player Ke Jie to become the world's No 1, ending thousands of years of human dominance（控制）in the game. AlphaGo is an artificial intelligence（AI）Go-playing program{#blank#}1{#/blank#}

    Artificial intelligence（AI）is usually defined as the science of marking computers do things that require intelligence when done by humans.{#blank#}2{#/blank#}These include learning, reasoning, problem-solving, perception, and language-understanding.

    {#blank#}3{#/blank#}In fact we are increasingly depending. upon computer-based artificial intelligence. As Charlie Qrtiz said, head of AL at the Massachusetts-based software company Nuance Communication, “It has opened a window for us.”Smartphones, self-driving cars, intelligent robots，etc. are constantly coming into our life. According to a recent survey, half of the world's AI experts believe human level machine intelligence will be achieved by 2040. This will open up huge possibilities for the enrichment of mankind, from tackling climate change and treating disease to labour- saving devices.

    {#blank#}4{#/blank#}Physicist Stephen Hawking last year warned that unless we take care, board games might be the least of it. “The development of full artificial intelligence could mean the end of the human race.”{#blank#}5{#/blank#}They believe AlphaGo's victory is a reminder of how fast the world is overcoming the obstacles in the way of AI, and its distribution in the world about us. Although there may yet be no evidence that computers will ever shake off their human masters, we should still treat these development with the humility and caution they deserve.

A. Other scientists have also expressed the concern.

B. Artificial intelligence has both advantages and disadvantages.

C. Defeating a human Go master is not the only thing AI can do.

D. Artificial intelligence will bring us disasters instead of benefits.

E. It was designed by an American Artificial intelligence company.

F. Not all experts hold the optimistic attitudes to the development of AI.

G. Research in AI has so far focused on some special fields of intelligence.

The Science of Risk-Seeking

    Sometimes we decide that a little unnecessary danger is worth it because when we weigh the risk and the reward, the risk seems worth taking. {#blank#}1{#/blank#} Some of us enjoy activities that would surprise and scare the rest of us. Why? Experts say it may have to do with how our brains work?

    The reason why any of us take any risks al all might have to do with early humans. Risk-takers were better at hunting, fighting, or exploring. {#blank#}2{#/blank#} As the quality of risk-taking was passed from one generation to the next, humans ended up with a sense of adventure and a tolerance for risk.

    So why aren't we all jumping out of airplanes then? Well, even 200,000 years ago, too much risk-taking could get one killed. A few daring survived, though, along with a few stay-in-the-cave types. As a result, humans developed a range of character types that still exists today. So maybe you love car racing, or maybe you hate it. {#blank#}3{#/blank#}

    No matter where you are on the risk-seeking range, scientists say that your willingness to take risks increases during your teenage years. {#blank#}4{#/blank#} To help you do that, your brain increases your hunger for new experiences. New experiences often mean taking some risks, so your brain raises your tolerance for risk as well.

    {#blank#}5{#/blank#} For the risk-seekers a part of the brain related to pleasure becomes active, while for the rest of us, a part of the brain related to fear becomes active.

As experts continue to study the science of risk-seeking, we'll continue to hit the mountains, the waves or the shallow end of the pool.

A. It all depends on your character.

B. Those are the risks you should jump to take.

C. Being better at those things meant a greater chance of survival.

D. Thus, these well-equipped people survived because they were the fittest.

E. This is when you start to move away from your family and into the bigger world.

F. However, we are not all using the same reference standard to weigh risks and rewards.

G. New brain research suggests our brains work differently when we face a nervous situation.

    If something that you're doing doesn't challenge you, then it doesn't change you. We all need some normal stress in our lives, after all. {#blank#}1{#/blank#} So challenge the following limits:

    ⒈Figure out what you're scared of and do it continuously.

    If you're a salesman, and you're scared of talking to people personally or over the phone now, instead of being scared and thinking you'll fail, spend at least five minutes a day to pick up the phone and make a call. {#blank#}2{#/blank#} But don't stop on the first try! Eventually, you can look at fear in the eye and say, "Go on. I'm not scared!"

    ⒉Take a class for a hobby you've been wanting to develop

    Make sure this hobby is not linked to your career; you have to relax and relieve your stress while performing this. {#blank#}3{#/blank#}Apart from helping you challenge yourself, taking a class for your hobby may also give you extra income.

    ⒊Set aside at least nine minutes a day for physical exercise.

    {#blank#}4{#/blank#}A simple 9-minute run around your neighborhood can do wonders for yourself. Exercise can not only help you maintain your regular weight  but also make you feel better about yourself.

    ⒋Travel and allow yourself to be interested in new people.

    Don't just limit yourself to your fellow travelers­try to connect with the service staff. You never know what kind of people they're going to be. Get out of your house or go online right now to book your class. {#blank#}5{#/blank#}

A. You should do it continuously.

B. Someone may hang up on you.

C. You don't need to go to the gym.

D. Running in the gym may be a better choice.

E. Start to travel now and learn to challenge yourself.

F. Some examples might be cooking, sewing, painting and so on.

G. You can never see any improvement if you stick to your comfort zone.

How to gain happiness? Aristotle, a famous Greek philosopher（哲学家）, believed that happiness is achieved through the development of certain virtues, stressing a balanced lifestyle. {#blank#}1{#/blank#}.

Balancing Personal Strengths and Relationships

Aristotle combined virtues like modesty, honesty, and sociability into one principle: balance knowing yourself with getting along with others. Modesty（谦虚）involves recognizing both your true strengths and weaknesses clearly. {#blank#}2{#/blank#}. Honesty means being true in your expressions. Sociability stresses the necessity of making and keeping friends.

Managing Emotions and Actions

{#blank#}3{#/blank#}. Aristotle said it's normal to feel emotions like anger, but the key to happiness is how you handle these feelings. Justice（公平）involves treating others fairly and balancing one's needs with the needs of others. Strength involves facing fears and carefully considering risks before acting, which helps you achieve your goals confidently.

Practicing Kindness and Tolerance（宽容）

Generosity, tolerance, and grace are virtues that Aristotle considered to be part of kindness. Generosity isn't just about giving things to others, but also about doing so thoughtfully. {#blank#}4{#/blank#}. Grace combines a sense of humor with the seriousness required in certain situations, helping to keep a pleasant and supportive presence around others.

{#blank#}5{#/blank#}. He teaches us that happiness is not just about seeking pleasure or avoiding pain, but about developing a balanced character. By developing these virtues and finding a balance in everything we do, we can lead truly happy and satisfying lives.

A. Aristotle stressed the importance of knowing oneself

B. This principle combines self-control, justice, and strength

C. Such realistic self-view makes you more confident and happier

D. Tolerance involves excusing others' mistakes while keeping self-respect

E. In short, Aristotle's approach to happiness is about finding balance in life

F. Here's a simple explanation of his ideas designed for high school students

G. A person who knows how to be happy needs to develop a balanced sense of justice

Signs of Healthy Friendships

Once in a while it's helpful to see if your friendship is as healthy as it can be. You might get used to a friendship over time to the point where you don't see the room for improvement. And since great friendships are priceless, you should always surround yourself with the kind of people who will lift your spirits, make you laugh, and remind (提醒) you that you are loved. {#blank#}1{#/blank#} Here are characteristics (特征) that strong friendships share.

{#blank#}2{#/blank#}

Friends make you feel comfortable with yourself, so you don't need to act like someone you're not. Your friends know your shortcomings and love you anyway. You are perhaps the "best version" of yourself when you're with your friends.

A healthy friendship includes plenty of gentle honesty. True friends won't pretend just to avoid an argument (争论). {#blank#}3{#/blank#} As a result, you'll know where you stand with your friends and won't be afraid to share your true opinions.

They argue in a healthy way.

One of the biggest misunderstandings about good friends is that they never fight. But let's face it everyone fights. {#blank#}4{#/blank#} In fact, voicing your opinions freely will cause you to disagree from time to time and that's okay.

Healthy friendships mean you can be friends with someone else, too.

{#blank#}5{#/blank#} That's why great friends will improve your relationship yet still encourage you to meet people and try new things without them. A healthy friendship means that sometimes the two of you spend time apart, and that's okay.

A. Arguing isn't unhealthy.

B. Is your friendship as healthy as it can be?

C. Good friends dine out together from time to time.

D. Good friends are real and honest with each other.

E. With an unhealthy friendship, you know clearly that something is "off".

F. Even if you have the best friend, it doesn't hurt to expand your social circle.

G. In a positive friendship, your friends won't lie to you, and they won't hurt your feelings either.