Eating too much fatty food, exercising too little and smoking can raise your future risk of heart disease．But there is another factor that can cause your heart problems more immediately: the air you breathe.

    Previous studies have linked high exposure (暴露）to environmental pollution to an increased risk of heart problem, but two analyses(分析) now show that poor air quality can lead to heart attack or stroke (中风）within as little as a few hours after exposure．In one review of the research, scientists found that people exposed to high levels of pollutants (污染物）were up to 5% more likely（可能的） to suffer a heart attack within days of exposure than those with lower exposure．A separate study of stroke patients showed that even air that the U．S．Environmental Protection Agency (EPA) considers to be of “moderate” (良好）quality and relatively safe for our health can raise the risk of stroke as much as 34% within 12 to 14 hours of exposure.

    The authors of both studies stress（强调）that these risks are relatively（相对的）small for healthy people and certainly modest compared with other risk factors such as smoking and high blood pressure．However, it is important to be aware of these dangers because everyone is exposed to air pollution regardless of lifestyle choices．So stricter regulation（规章制度）by the EPA of pollutants may not only improve environmental air quality but could also become necessary to protect public health.

    If you want to become a fluent English speaker you should take some advice. There are four skills in learning English. They are reading, listening, speaking, and writing. The most important thing you must remember is that if you want to improve your speaking and writing skills, you should first master the skills of reading and listening.

    Read as much as you can. But your reading must be active. It means that you must think about the meaning of the sentence, the meaning of the unfamiliar（不熟悉） words, etc. There is no need for you to pay much attention to grammars or try to understand all the unfamiliar words you come across, but the fact that you see them for the first time and recognize them whenever you see them, for example, in other passages or books, is enough. It would be better to prepare yourself a notebook so you can write down the important words or sentences in it.

    As for listening, there are two choices: besides reading, you can listen every day for about 30 minutes. You can only pay attention to your reading and become skillful at your reading, then you can catch up on your listening. Since you have lots of inputs in your mind, you can easily guess what the speaker is going to say. This never means that you should not practice listening.

    For listening you can listen to cartoons or some movies that are specially made for children. Their languages are easy. Or if you are good at listening you can listen to VOA or BBC programs every day. Again the thing to remember is being active in listening and preferably taking some notes.

    If you follow these pieces of advice, your speaking and writing will improve quickly, and you can be a fluent English speaker one day.

    Tyler Skiuzacek's father，Patrick，could not sleep through the night．It was 2007，and Patrick had just returned from a year in Iraq，where he served in the U．S．Army．Patrick Skluzacek was energetic and happy when he left for Iraq，Tyler says．But when he returned，he was unhappy and drinking alcohol too much．It turned out Patrick was suffering from sleep panic attacks．Patrick would wake up every night．His heart would beat too fast．He would sweat．The nighttime panic attacks prevented Patrick from feeling good the next day，because he was so tired．

    Almost 10 years later，Tyler was in a position to help his father．He thought he could make a computer program that might help his father．So he entered a competition in Washington，D．C，trying to solve the problem Tyler's father and other U．S．war veterans(老兵)，were having．People called them “night terrors.”The students had 36 hours to come up with a program．They called it myBivy．That name comes from bivouac，a military term for a safe place to sleep．

    The application uses a smart watch and a smart phone together．The watch tracks the wearer's heartbeat．It sends the data to the program on the smart phone．Research shows that a person's heart rate will increase right before a night terror．So if the wearer's heartbeat started to rise，my B ivy would respond．The smart watch would vibrate(振动)and gently wake up the sleeping person．That was enough to prevent a night terror from happening．

    Patrick wore the watch for two weeks to get used to it．Then，Tyler turned on the application．On the first night，the vibrations from the watch prevented 10 nightmares．Patrick said he had not slept that well in many years．Tyler and his team won the contest in Washington，D．C．The prize was $1，500．Then the group tried to raise more money from investors，and they were surprised when they took in over$25，000．By the spring of 2016，Tyler and his team were testing the app with volunteers，and hoped to make it availab1e to the public soon．

    People do not analyze every problem they meet. Sometimes they try to remember a solution from the last time they had a similar problem. They often accept the opinions or ideas of other people. Other times they begin to act without thinking. They try to find a solution by trial and error. However, when all these methods fail, the person with a problem has to start analyzing. There are six stages in analyzing a problem.

    First the person must recognize that there is a problem. For example, Sam's bicycle is broken, and he cannot read it to class as he usually does. Sam must see that there is a problem with his bicycle.

    Next the thinker must define the problem. Before Sam can repair his bicycle, he must find the reason why it does not work. For instance, he must determine if the problem is with the gears, the brakes, or the frame. He must make his problem more specific.

    Now the person must look for information that will make the problem clearer and lead to possible solutions. For instance, suppose Sam decided that his bike does not work because there is something wrong with the gear wheels. At this time, he can look in his bicycle repair book and read about gears. He can talk to his friends at the bike shop. He can look at his gears carefully.

    After studying the problem, the person should have several suggestions for a possible solution. Take Sam as an illustration. His suggestions might be: put oil on the gear wheels; buy new gear wheels and replace the old ones; tighten or loosen the gear wheels.

    Eventually one suggestion seems to be the solution to the problem. Sometimes the final idea comes very suddenly because the thinker suddenly sees something new or sees something in a new way. Sam, for example, suddenly sees that there is a piece of chewing gum between the gear wheels. He immediately realizes the solution to his problem: he must clean the gear wheels.

    Finally the solution is tested. Sam cleans the gear wheels and finds that afterwards his bicycle works perfectly. In short, he has solved the problem.

    Bad news sells. If it bleeds, it leads. No news is good news, and good news is no news. Those are the classic rules for the evening broadcasts and the morning papers. But now that information is being spread and monitored in different ways, researchers are discovering new rules. By tracking people's e-mails and online posts, scientists have found that good news can spread faster and farther than disasters and sob stories.

    "The 'if it bleeds' rule works for mass media," says Jonah Berger, a scholar at the University of Pennsylvania. They want your eyeballs and don't care how you're feeling. But when you share a story with your friends, you care a lot more how they react. You don't want them to think of you as a Debbie Downer."

    Researchers analyzing word-of-mouth communication—e-mails, Web posts and reviews, face-to-face conversations—found that it tended to be more positive than negative, but that didn't necessarily mean people preferred positive news. Was positive news shared more often simply because people experienced more good things than bad things? To test for that possibility, Dr. Berger looked at how people spread a particular set of news stories: thousands of articles on The New York Times' website. He and a Penn colleague analyzed the "most e-mailed" list for six months. One of his first findings was that articles in the science section were much more likely to make the list than non-science articles. He found that science amazed tines' readers and made them want to share this positive feeling with others.

    Readers also tended to share articles that were exciting or funny, or that inspired negative feelings like anger or anxiety, but not articles that left them merely sad. They needed to be aroused one way or the other, and they preferred good news to bad. The more positive an article, the more likely it was to be shared, as Dr. Berger explains in his new book, "Contagious: Why Things Catch on."

    My father loves his garden. He planted some seeds in it. But at that time I didn't understand why working in the dirt excited him so much.

    Unfortunately, in early May, my father was seriously injured in an accident. He had to stay in bed for a while. My mother had several business trips so she couldn't take care of the garden. I didn't want my father to worry, so I said that I would take care of his garden until he recovered. I assumed that the little plants would continue to grow as long as they had water, and luckily it rained fairly often so I didn't think much about the garden.

    One Saturday morning, my father said to me, "Christine, the vegetables should be about ready to be picked. Let's have a salad today!" I went out to the garden and was upset to see that many of the lettuce leaves and carrots had been half eaten by bugs. There were hundreds of bugs all over them!

    I panicked for a moment, but then I quietly went to the nearest store to buy some vegetables.

    When I gave the salad to him, he said, "Oh, Christine, what a beautiful salad! I can't believe the carrots are this big already. You must be taking very good care of my garden." I felt a little bit guilty.

    Coming home, my mother saw the bag from the supermarket in the kitchen. I was embarrassed and I admitted, "Dad wanted a salad, but the garden was a disaster. I didn't want to disappoint him so I went to the store." She laughed but promised to help me in the garden and weeks later I was finally able to pick some.

    I carefully made a salad and took it to my father. He looked at it with a hint of a smile. "Christine the carrots are smaller in this salad, but they taste better."

    Now, I better understand how putting a lot of effort into caring for something can help you appreciate the results more, however small they maybe. Perhaps this was one of the reasons for my father's love of gardening.