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,be;ow 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.

    The pursuit of longevity has long been on people's minds, prompting an abundance of research on the effects of food and diet on the human lifespan. According to recent research from the UC Irvine Institute, drinking coffee and wine could help you live longer.

    The 90+ Study evaluated more than 1,600 people over the age of 90 for their lifestyle habits and other qualities that might have contributed to their longevity.

    Participants were visited every six months, when they were given various tests. Researchers also collected information about the participants' diets, lifestyles, and medical histories.

    They found out that two of the habits that helped preserve lives the most are drinking alcohol and coffee. “I have no explanation for it,” admitted Dr Claudia Kawas, “but I do firmly believe that moderate (适度的) drinking improves longevity.” So should we all be drinking more coffee and wine? While that would be great news, the research may not be as definitive as it seems.

    “Most studies about alcohol consumption, including The 90+ Study, are observational, so we  can only say that something about drinking is associated with health and longevity,” registered dietitian Jennifer Markowitz told The Daily Meal.

    “I'd be curious to see if the coffee and alcohol drinkers shared other important habits or lifestyle factors that might also play into their longevity.”

    In other words, it might not be the wine and coffee that's helping people live longer, but the two substances do have some considerable health benefits. “Wine and coffee are packed with antioxidants(抗氧化剂) which are known to protect our bodies from damage caused by free radicals,” explained registered dietitian Keri Gans to The Daily Meal. “Research on antioxidants has shown several heath benefits, including the possibility they may lower the risk of type 2 diabetes, improve cognitive function, decrease the risk of dementia, and lower the risk of heart disease.”

    Moderate drinking can be beneficial according to other studies—so long as it's moderate.

    Tourism wasn't as important as it is today. In the past, only people with a good deal of money could travel on holidays to other countries. More people travel today than in the past because there is a growing middle class in many parts of the world; that is to say, people now have more money for travel. Special plane fares(费用) for tourists make travel less expensive and more attractive than ever before. One person doesn't travel for the same reason as another. But most people enjoy seeing countries that are different from their own. They also like to meet new people and to taste new food.

    Tourism causes many changes in a country and in people's lives. People build new hotels and restaurants and train native men and women as guides to show visitors interesting places. There're new nightclubs and other amusements. International tourism is clearly a big business.

    The World Health Organization recently said that it planned to add gaming disorder (游戏成瘾) to its new list of disease classifications, angering the gaming industry but pleasing doctors who hope it may make treatment more easily available.

    Some US experts said it would make little difference when it comes to helping people with the disorder, although others said it would bring attention to a disorder that people sometimes don't recognize. So some experts disagree WHO's plan.

    Many of us enjoy video games, but does playing our favorite game for a couple of hours every night mean we're suffering from gaming disorder? Not according to the WHO.

    The symptoms listed by the WHO include a lack of control over gaming, treating gaming more seriously than other life interests and daily activities, and continuing to play games despite the negative consequences that playing them might have.

    "The behavior pattern is enough to result in significant damage to one's personal, family, or social life." the WHO said.

    Meanwhile, Douglas Gentile of Iowa State University has carried out influential research into the cause of gaming addiction in young people." I and many others had assumed that gaming is not really a problem but is a symptom of other problems," he told NBC News. Many had thought it was simply a failure of self-control. To see if it was, Gentile's team studied a group of children who had been gaming for several years." We found that when kids became addicted, their anxiety increased … and their grades decreased," Gentile said. When kids were able to back off from gaming, their symptoms disappeared, he added.

    Gentile thinks medical organizations should pay attention to the WHO's proposal." This isn't an issue of opinion; it's an issue of science," he said." This is a major scientific and medical organization. They don't do things lightly and without reason."

    Dr Petros Levounis, chair of psychiatry at the New Jersey Medical School at Rutgers University, said that he hoped the WHO's proposal would lead to more research into obsessive (过度的) behavior among all types of people.

    "Now, there is renewed interest and excitement," he said. So some experts are in favour of WHO's plan.

    Fire fighting is a serious matter. Knowing what to do during a fire can save people's lives. It is important to know the ways you can use and show them to everyone else in the family, such as stairways and emergency exits, but not elevators.

    From the lower floors of buildings, escape through windows is possible. Learn the best way to get out from a window with the least chance of serious injury.

    The second floor window is usually not very high from the ground. An average person, hanging by the fingertips will have a drop of about 6 feet to the ground. It is about the height of an average man. Of course, it is safer to jump a short way down than to stay in a burning building.

    Windows are also useful when you are waiting for help. Be sure to keep the door closed before opening the window. Otherwise, smoke and fire may be drawn into the room. Keep your head low at the window to be sure you get fresh air rather than smoke that may have leaked(漏)into the room.

    On the second or third floor, the best windows for escape are those which open onto a roof. From the roof a person can drop to the ground more safely. Dropping onto cement might end in injury. Bushes and trees can help you to have a soft landing.

How to make the most of your time with your host family

Living and studying abroad can be a meaningful and enriching experience. And living with a host family is one of the best ways to immerse（沉浸） yourself in the culture. {#blank#}1{#/blank#} Here are some tips on making the most of your time with your host family.

 {#blank#}2{#/blank#}. You have to understand that host families are sharing the living space with others just because they want to give a kid the opportunity to live abroad. They are willingly changing their lives so you can experience this! With their support, things become easier.

Many people struggle to feel comfortable with their host families at first. This is a completely normal feeling! You've just left everything you've known for years behind to start a new life. It's okay to be confused. {#blank#}3{#/blank#} While you may know the language, some expressions can be hard to understand at first. Be patient with yourself and remember that you will adapt but it will take some time.

Feeling at home can be difficult at the beginning. That's why spending time in common areas is necessary. If you spend all your time in your room, it's going to be hard to feel like you belong . Joining in everyday activities with your host family will help you create a family bond. For example, some families like having dinner together on weekends. Make time for those moments. {#blank#}4{#/blank#}.

Communication is key. If you are unsure about something, ask! It's normal to know few customs and habits at first, so instead of doing things blindly, just ask. Your host family will understand and help you. {#blank#}5{#/blank#} When you are out with your host family, ask them about these, and keep learning them when you are on your own!

A. The language barrier（障碍） can also be a struggle.

B. Showing gratitude will take you a long way.

C. Keep in mind that when in Rome, do as the Roman s do.

D. Then, you'll have chances to expose yourself to their language.

E. It's also normal not to know a lot about unspoken social rules of the country.

F. Not only will they appreciate it but you will also feel like a part of their world.

G. However, living with a foreign family can be difficult and adapting to it can take some effort.