The more hours that young children spend in child care, the more likely they are to turn out aggressive and disobedient by the time they are in kindergarten, according to the largest study of child care and development ever conducted. Researchers said this correlation (相关性) held true regardless of whether the children came from rich or poor homes, were looked after by a relative or at a center, and whether they were girls or boys.

    What is uncertain, however, is whether the child care actually causes the problem or whether children likely to turn out aggressive happen to be those who spend more hours in child care. It also remains unclear whether reducing the amount of time in child care will reduce the risk that a child will turn into a mean person. What's more, quality child care is associated with increased skills in intellectual ability such as language and memory, leading some academics to suggest that child care turns out children who are “smart and naughty”.

    The government-sponsored research, which has tracked more than 1,300 children at 10 sites across the country since 1991, is bound to cause the debate over child care again: How should people balance work and family? And how should parents, especially mothers. Resolve the demands that are placed on them to be both breadwinners and supermoms?

    That debate was already on display at a news briefing yesterday, where researchers themselves had different opinions about the data and its implications (含义). “There is a constant relationship between time in care and problem behavior, especially those involving aggression and behavior,” said Jay Belsky of Birkbeck College in London, one of the lead investigators of the study who has previously annoyed women's groups because of his criticisms of child care. “On behalf of fathers or mothers?” interrupted Sarah Friedman, a developmental psychologist at the National Institute of Child Health and Human Development (NICHD) and one of the other lead scientists on the study. “On behalf of parents and families,” responded Belsky.

    “NICHD is not willing to get into policy recommendations.” said Friedman, contradicting her colleague. “There are other possibilities that can be entertained. Yes it is a quick solution—more hours in child care is associated with more problems. The easy solution is to cut the number of hours but that may have implications for the family that may not be beneficial for the development of the children in terms of economics.” In an interview after the briefing, Friedman said that asking parents to work fewer hours and spend more time with their children usually meant a loss of family income, which adversely(不利地) affects children.

    Scientists said that the study was highly reliable. But the researchers said they had no idea whether the behavioral difficulties persisted as the children moved to higher grades.

    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.

    In a foreign country, a man visited a local restaurant. He didn't speak their language. He ordered something indecipherable off the menu. When the waiter brought him a plate of delicious looking fried noodles, he smiled and made an OK sign at the waiter with his thumb and forefinger linked in a circle. Looking angry, the waiter then picked up the dish and thrown it to his lap. What he did wrong, he wondered. Well, nothing is quite as it seems when it comes to using hand gesture in another country.

    Gestures have been used to replace words in many countries, and they are often specific to a given culture. Gesture may mean something complimentary in one culture, but is highly offensive in another.

    The gesture “thumb-up” is commonly misinterpreted. In English, it is popularly known as 'thumbs up', despite the fact that the action is commonly performed with only one hand. English-speaking Caucasians use it to signal 'OK', which is the same meaning as O.K. ring gesture. The two can in fact be used almost interchangeably.

    Avoid using this gesture in Southern Sardina or Northern Greece unless you want to invite a fight. While American, British and Australian would use the thumb up to signal hitch-hiking to the drivers, this message will not encourage a Greek driver or motorist to stop to give them a ride.

    There are no right or wrong signals, only cultural differences. Lack of cultural understanding will lead to disharmony among people from different cultures. When we know what to look for, such encounters with other cultures are actually very interesting, fascinating and fun. It is certainty a great topic to discuss over a cup of coffee and cakes.

    The Healthy Habits Survey shows that only about one third of American seniors have correct habits. Here are some findings and expert advice.

    ⒈How many times did you brush your teeth yesterday?

    Finding: A full 33% of seniors brush their teeth only once a day.

    Step: Remove the 300 types of bacteria in your mouth each morning with a battery-operated toothbrush. Brush gently for 2 minutes, at least twice a day.

    ⒉How many times did you wash your hands or bathe yesterday?

Finding: Seniors, on average, bathe fewer than 3 days a week. And nearly 30% wash their hands only 4 times a day—half of the number which doctors recommend.

    Step: We touch our faces around 3,000 times a day-often inviting germs（病菌）to enter our mouth, nose, and eyes. Use toilet paper to avoid touching the door handle. And, most important, wash your hands often with hot running water and soap for 20 seconds.

    ⒊How often do you think about fighting germs?

    Finding: Seniors are not fighting germs as well as they should.

    Step: Do you know it is not your toilet but your kitchen sponge（海绵）that can carry more germs than anything else? To kill these germs, keep your sponge in the microwave for 10 seconds.

    Knowing what to do at checkout and properly preparing for it can turn a potentially heated situation into a quick thank you add goodbye. Below we made a list of five things you should remember at hotel checkout.

Don't be late to check

    Hotels may add an extremely high price for being just a half hour late. If you know you won't make the cutoff time, it never hurts to call ahead and try to negotiate away a potential charge.

    Don't forget to double cheek the room and safe

    Make sure you don't leave things behind. If you have an early flight or checkout time, pack up as much as you can the night before so that last-minute rush isn't too annoying. Also, be sure to take out anything in the room safe.

    Don't forget to tip the housekeepers

    It's always polite to leave some money for the people keeping your room clean.

    Don't ignore the detailed bill

    You may be in a rush, but give the detailed hill a careful look to see if the hotel charge is different from the rate you initially booked.

    Don't get angry

    Shooting at the assistant manager standing behind the front desk probably won't help.

    When dealing with an unexpected item on the bill. Think about how difficult it can be to deal with annoyed customers. Keep calm and things may be solved better and sooner.

    Time talks. It speaks more plainly than words. Time communicates in many ways.

    Consider the different parts of the day, for example. The time of the day when something is done can give a special meaning to the event. It is not customary to telephone someone every early in the morning. If you telephone him early in the day, the time of the call shows that the matter is very important and requires immediate attention. If someone receives a call during sleeping hours, he assumes it is a matter of life or death. The time chosen for the call communicates its importance.

    In social life, time plays a very important part. In the United States, guests tend to feel they are not highly regarded if the invitation to a dinner party is extended only three or four days before the party date. But this is not true in all countries. In other areas of the world, it may be considered foolish to make an appointment too far in advance because plans which are made for a date more than a week away tend to be forgotten.

    The meaning of time differs in different parts of the world. Thus, misunderstandings often arise between people from cultures that treat time differently. Promptness(准时) is valued highly in American life, for example. If people are not prompt, they may be regarded as impolite or not fully responsible. In the U.S., no one would think of keeping a business partner waiting for an hour; it would be too impolite. A person who is five minutes late is expected to make a short apology.

    This way of treating time is quite different from that of several other cultures. This helps to explain the unfortunate experience of a certain agriculturist from the United States, assigned to duty in another country. After a long delay, the agriculturist was finally agreed an appointment with the Minister of Agriculture. Arriving a little before the appointed hour, the agriculturist waited. The hour came and passed. At this point he suggested to the secretary that perhaps the minister did not know he was waiting in the outer office. This gave him the feeling of having done something to solve the problem, but he had not. Twenty minutes passed, then thirty, then forty-five. To an American, that is the beginning of the "insult period". No matter what is said in apology, there is little that can remove the damage done by an hour's wait in an outer office. Yet in the country where this story took place, a forty-five-minute waiting period was not unusual.

    In the West, particularly in the United States, people tend to think of time as something fixed in nature. As a rule, Americans think of time as a road stretching into the future, along which one progresses. The road has many sections, which are to be kept separate— "one thing at a time". People who cannot plan events are not highly regarded. Thus, an American may feel angry when he has made an appointment with someone and then finds a lot of other things happening at the same time.

    Since time has such different meanings in different cultures, communication is often difficult. We will understand each other a little better if we can keep this fact in mind.