Think about vitamin D when you're catching up on summer rays. It's sometimes called the “sunshine vitamin” because it's produced in your skin in response to sunlight. Vitamin D is a fat-soluble (脂溶性的) vitamin in a family of compounds that includes vitamins D-1, D-2, and D-3. It can affect as many as 2,000 genes in the body.

    Vitamin D has several important functions. Perhaps the most vital are regulating the absorption of calcium and phosphorous（磷）, and promoting normal immune system function. Getting enough vitamin D is important for normal growth and development of bones and teeth, as well as improving resistance against certain diseases.

    In addition to its primary benefits, research suggests that vitamin D may also play a role in: reducing your risk of multiple sclerosis（多发性硬化）, according to a 2006 study published in the Journal of the American Medical Association decreasing your chance of developing heart disease, according to 2008 findings published in Circulation helping to reduce your possibility of developing the flu, according to 2010 research published in the American Journal of Clinical Nutrition regulating mood and warding off depression losing weight or preventing heart disease.

    How do you get it? Your body produces vitamin D naturally when it is directly exposed to sunlight. A little can go a long way. All you need is 10 minutes a day of midday, pre-sunscreen sun exposure,especially if you have fair skin. Besides getting vitamin D through sunlight, you can also get it through certain foods and supplements to ensure adequate levels of the vitamin in your blood.

Advice for High School Students

    As a person who is graduating from high school very soon, I have some suggestions for students in high school or students who are soon going to be high school students. {#blank#}1{#/blank#} I am sure others can benefit from reading them and will not make similar mistakes like me.

    {#blank#}2{#/blank#} Do not value first impression highly. Don't dismiss a person or an idea too early just because you immediately get a bad impression. You will miss many opportunities because of that. Although something seems bad at the first impression, it does not mean it is bad all the time. Try to give everything a fair chance.

    Don't try to please everybody. There is no way you can please everybody or get everybody to agree with you. {#blank#}3{#/blank#} It is a huge waste of time.

    Have respect for authority. No matter how much you may dislike them, just remember that teachers and parents care about you and they are only doing their jobs. {#blank#}4{#/blank#} Don't argue with them and just obey them.

    Realize a high school is not the real world. The real world isn't a closed environment. {#blank#}5{#/blank#} What is rewarded in high school such as popularity and agreement is different from what is rewarded in the real world. If high school isn't working out for you, you may find yourself better at handling the real world.

A. Do not be too quick to judge.

B. So just learn to say the word “No” a lot.

C. Listen to their advice and consider it carefully.

D. Many of these are based on regrets that I have.

E. Bad habits are hard to break and remain with you for a long time.

F. Don't spend any effort trying to please others who will never like you.

G. It is a free society where people accept responsibility for their actions.

    Many people trying to sell homes find that an increase in home prices has turned the market in their favor. But sellers can still get the short end of the deal if they aren't careful. Here are a few tips for you:

    Don't test your luck. Of course you think anyone who moves into your lovely home should be willing to pay top dollars, especially if you've recently invested in some improvements. But listing a home at a price that's too high above the market price could turn away some buyers.

    Buyers noticing that the home still hasn't sold may begin to assume there's something wrong with the house and use that as a reasonable excuse for offering a lower price. And if a home hasn't received any offers after two weeks, it might be time to reset the price.

    A price that's too low can bring about an undesired outcome. Listing your home at or slightly below the market price can have the effect of drawing in a large group of buyers and increase the chances that a home will receive multiple offers. But setting the price too low comes with several risks. One possibility is that buyers will get skeptical of the home that is listed for $ 15,000 to $ 20,000 less than similar homes in the area, especially if it's not properly marketed. Once again, people might assume there is something wrong with the home and may not bother to look at it.

    Spy on the competition. Going to other people's open houses can give you a better sense of how your home compares to others on the market. Check out the finishes in their kitchens, the size of their backyards and use the information to figure out where your home should fit in the range of the price. But don't set your pricing just on what you see elsewhere.

    Camping wild is a wonderful way to experience the natural world and, at its best, it makes little environmental influence. But with increasing numbers of people wanting to escape into the wilderness, it is becoming more and more important to camp unobtrusively (不引人注目地) and leave no mark.

    Wild camping is not permitted in many places, particularly in crowded low—land Britain. Wherever you are, find out about organizations responsible for managing wild spaces, and contact them to find out their policy on camping and shelter building. For example, it is fine to camp wild in remote parts of Scotland, but in England you must ask the landowner's permission, except in national parks.

    Camping is about having relaxation, sleeping outdoors, experiencing bad weather, and making do without modem conveniences. A busy, fully—equipped campsite (野营地) seems to go against this, so seek out smaller, more remote places with easy access to open spaces and perhaps beaches. Better still, find a campsite with no road access; walking in makes a real adventure.

    Finding the right spot to camp is the first step to guaranteeing a good night's sleep. Choose a campsite with privacy and minimum influence on others and the environment. Try to use an area where people have obviously camped before rather than creating a new spot. When camping in woodland, avoid standing dead trees, which may fall on a windy night. Avoid animal runs and caves, and possible homes of biting insects. Make sure you have most protection on the windward side. If you make a fire, do so downwind of your shelter. Always consider what influence you might have on the natural world. Avoid damaging plants. A good campsite is found, not made—changing it should be unnecessary.

    How often do you exercise? A new study found that most kids aged 12 to 15 weren't getting enough physical activity. The results were based on about 800 kids. As part of the study, the kids tracked and reported on their own activity levels, and took physical exams.

    U. S. fitness guidelines suggest an hour or more of physical activity every day. According to the study, only 1 in 4 U.S. kids get enough physical activity.

    "It's certainly worrying to see that our kids have such a limited amount of physical activity each day," said Dr. Stephen Pont. He is an expert on children's health.

    Few kids in the study met the guidelines on physical activity that raises the heart rate and makes people breathe harder. Overall, about 25% said they got an hour of that kind of exercise every day. Kids also reported on which activities they did most often outside of school gym class--basketball for boys and running for girls.

    The study found that fat teenagers were less active than normal-weight girls and boys. Fat girls were slightly less active than normal-weight girls, but levels were similar among overweight and normal-weight boys. The study also said that the percent of fat children aged 2 to 19 was 17%, or about 12.5 million kids.

    "There's always room for improvement," said Tala Fakhouri, who was the leader of the study. She also said the results provide useful information to help with fitness campaigns such as Let's Move, which was initiated by Michelle Obama in 2010. To inspire kids to eat right and get in shape, Michelle visits schools and holds exercise events. She also calls on schools to offer regular gym classes.

    The study also found kids who get physical education at school may get better grades.

    A recent documentary produced by the British Broadcasting Corporation (BBC) has caused a stir in China and in the UK.

    The documentary, titled Are Our Kids Tough Enough? focuses on five Chinese teachers who are sent to teach 50 UK teens at a school in Hampshire.

    The teachers instruct the students for a month. The pupils are then tested, and the results are compared to the ones of those who have continued in the regular UK education system. The idea is to see if the Chinese method improves academic performance.

    The Chinese teachers use their own teaching methods but receive strong resistance from the students. A clip from the documentary online shows some problems, with Chinese teachers calling their students lazy and lacking in discipline, while the students say the high pressure and harsh teachers are driving them crazy.

    This has aroused a new debate in both China and the UK, with some arguing the teenagers need more regulation and discipline. Others say Chinese methods encourage rote learning (死记硬背) instead of independent thinking. For instance, Chinese language teachers should do more than pass on knowledge about words and characters. They should inspire students, helping them feel the sentiment from Chinese literature. This is a higher level of teaching.

    Yang Dongping, dean of the 21st Century Education Research Institute, says, "The Chinese teaching methods are designed to strictly train the majority. Foreign teaching methods, however, are more natural and relaxing, and designed to inspire students' interest in learning. Education methods are based on culture. That is why a successful education method in one place may not work that well when simply 'transplanted' into another place."

    Yang Dongping says, "The documentary does reflect some problems rooted in traditional Chinese teaching methods. Nobel prize winner, Yang Zhenning, gave a very fair comment on this issue. He said the Chinese-style education method works for most ordinary qualified students effectively, helping them reach high standards. However, it may weaken the training for high-potential outstanding students."