It is bad to have food stuck between your teeth for long periods of time. This is because food attracts germs; germs produce acid, and acid hurts your teeth and gums. Flossing (使用牙线) helps to remove the food that gets stuck between your teeth. This explains why flossing helps to keep your mouth healthy, but some doctors say that flossing can also be good for your heart.

    It may seem strange that something you do for your teeth can have any effect on your heart. Doctors have come up with a few ideas about how flossing works to keep your heart healthy. One idea is that the germs that hurt your teeth can leave the mouth and travel into your blood.Germs that get into the blood can then attack your heart. Another idea is based on the fact that when there are too many germs in your mouth, the body tries to fight against there germs. For some reason, the way the body fights these mouth germs may end up weakening the heart overtime.

    Not every doctor agrees about these ideas. Some doctors think that the link between good flossing habits and good heart health is only a coincidence. The incidence (发生率) of two or more events is completely random, as they do not admit of any reliable cause and effect relationship between them. For example, every time I wash my car, it rains. This does not mean that when I wash my car, I somehow change the weather. This is only a coincidence. Similarly, some doctors think that people who have bad flossing habits just happen to also have heart problems, and people who have good flossing habits just happen to have healthy hearts.

    The theory that flossing your teeth helps to keep your heart healthy might not be true. But every doctor agrees that flossing is a great way to keep your teeth healthy. So even if flossing does not help your heart, it is true to help your teeth. This is enough of a reason for everyone to floss their teeth every day.

    Rainy days don't have to get you down, a happiness expert has reported.

    Paul Dolan, Professor of Behavioral Science at the London School of Economics, said that people only feel miserable in bad weather because they think about it too much. Studies have shown that people who live in warm, sunny climates are no happier than those in chilly, wet climates, he says. So the British talking about the weather may be making us gloomier（沮丧的） than the weather itself.

    He said: “A study was done that measured the happiness levels of people in California compared to the North West. “They expected that people in California would be happier because it is more sunny, but they found that levels of happiness were exactly the same. If it is sunny every day you get used to it and the sunshine doesn't make you any happier. Most of the time the weather doesn't influence our well-being at all. But when we think about it, and think that it does, that's when we get miserable.”

    In his new book, Happiness By Design, Dolan argues that we can think ourselves happy by taking our attention away from what makes us sad.

    “Most of our anxieties come from what might be,” he argues. “If you want to be happier, pay attention to the things that make you feel good.”

    He also claimed that a problem shared was not always a problem halved(减半). He believed that humans are actually very good at being able to get over tragedy(悲剧) and loss.

    Professor Dolan also admitted for the first time that he had a stammer（口吃）, which had made his early life miserable. He added it only got better when he learned not to pay attention to his speech problem.

    “Things are never as bad as you imagine them being,” he said.

    People with an impulsive personality refer to those who tend to do things without considering the possible dangers or problems first. According to a new study by researchers at the University of Georgia, such people may be more likely to have food addiction. The study found that people exhibiting impulsive behavior weren't necessarily overweight, but impulsiveness was related to a direct relationship with food, and therefore, less healthy weight.

    Food addiction has been compared to addictive drug use. Studies have linked the dopamine (多巴胺) release that occurs after tasting delicious food to the dopamine release that happens when people consume other addictive substances.

    Impulsive behavior involves several personality traits (特点). Two of these traits, known as negative urgency and lack of perseverance, were particularly associated with food addiction and high BMI (身体质量指数) during the study.

    Negative urgency is characterized by the tendency to behave impulsively when experiencing negative emotions. Some people might drink alcohol or take drugs. For others, it could mean eating to feel better. Lack of perseverance is when a person has a hard time finishing hard or boring tasks. People with a lack of perseverance might have difficulty attempting to change addictive eating behavior, which could also cause obesity.

    “Impulsiveness might be one reason why some people eat in an addictive way despite motivation to lose weight,” said Dr. Ashley Gearhardt, a clinical psychologist. He was involved in developing the Yale Food Addiction Scale in aid of those people. “We are theorizing that if food addiction is really a thing, then our measure, the Yale Food Addiction Scale, should be related to helping control impulsive action,” said Gearhardt.

    Clinical psychologist Dr. James MacKillop, whose lab was conducting the study, believes that therapies used to treat addictive drug behavior could help people who suffer from addictive eating habits.

    “Most of the programs for weight loss at this point focus on the most obvious things, which are clearly diet and exercise,” MacKillop said. “It seems that managing strong desires to eat would naturally fit in with the skills a person would need to eat healthily.”

    When I was about 5 years old, I experienced my very first random act of kindness. I was sitting at the roadside one evening, crying alone for some reason when suddenly, a boy came up to me and gave me a plastic rose, I remember the moment when I took the rose from his hand; I was smiling from ear to ear, whispering "I want to be like him" to myself as I watched him walking away.

    From then on, I made it as my life mission to do random acts of kindness whenever I can. I was very determined to make other people smile. That was the only reason why I joined my school's Red Crescent Society and became a volunteer. Unfortunately, not everyone thinks in the same way as I did. Whenever I do something nice to others, people around me will start to judge my actions. Often I will just keep quiet and ignore what they say, but every once in a while, they do drive me up the wall.

    These people like to complain about how humans nowadays are lacking of humanities and compassion. However, when they actually see somebody doing a good deed in front of them, they start to question and criticize that person's honesty. Perhaps it is the increasing crime rate and the never-ending rat race that caused them to be so suspicious to nice strangers. In other words, people nowadays have lost sight of the real meaning of kindness and just let it go unnoticed. That is why I think random acts of kindness are really important. These selfless acts are not only capable of bringing joy to the receivers but also to the givers. Because of this, I want to help spread the idea of these random acts to the whole world. I want to show the people how the little things they give could make a big difference in someone else's life.

    Kids and science seem to be made for each other!

    The basic science is a combination of thought and experiment called the scientific method. It's where you start with an idea, create a way to prove or disprove your idea, and show what you learned based on facts. Learning to follow this process helps you think logically (逻辑地) and carefully. These important thinking skills can be used in many areas of study. To give a child practice with these thinking skills is like giving vitamins (维生素) to a developing mind.

    One of the greatest things we can teach our children is to love learning. Learning science is a great way to do so. Children are easy to be interested in science. Because much of science is hands­on, it attracts most children. Nothing makes a child sit up and take notice like the "WOW!" of a great science showing.

    Science opens doors to many subjects at school. Building love for science can be helpful in other areas of study. For example, one cannot love science for very long without becoming good at its language — math! So science encourages children to study math. An interest in science is an interest in how things were once understood compared to how they are understood now. Thus studying science lends itself easily to studying history. And after you do an experiment, you need to write a lab report. Therefore, writing becomes an important part of science.

    Science is the basic thing for much of our life. The science of farming shows how our food is produced; biomedical science keeps us healthy; even our beds these days are designed according to scientific facts. We almost eat, sleep and breathe with the help of science! When we prepare the next generation (一代) of voters, creators, and policy makers, it is important to make sure they are not only comfortable but also good at science.

    Next month, I'm traveling to a remote area of Central Africa and my aim is to know enough Lingala — one of the local languages — to have a conversation. I wasn't sure how I was going to manage this — until I discovered a way to learn all the vocabulary I'm going to need. Thanks to Memrise, the application I'm using. It feels just like a game.

    "People often stop learning things because they feel they're not making progress or because it all feels like too much hard work," says Ed Cooke, one of the people who created Memrise. "We're trying to create a form of learning experience that is fun and is something you'd want to do instead of watching TV."

    Memrise gives you a few new words to learn and these are "seeds" which you plant in your "greenhouse". When you learn the words, you "water your plants". When the application believes that you've really memorized a word, it moves the word to your "garden". And if you forget to log on, the application sends you emails, reminding you to "water your plants".

    The application uses two principles about learning. The first is that people memorize things better when they link them to a picture in their mind. Memrise translates words into your own language, but it also encourages you to use "mems". For example, I memorized motele, the Lingala word for "engine", using a mem I created — I imagined an old engine in a motel (汽车旅馆) room.

    The second principle is that we need to stop after studying words and then repeat them again later, leaving time between study sessions. Memrise helps you with this, because it's the kind of application you only use for five or ten minutes a day.

    I've learnt hundreds of Lingala words with Memrise. I know this won't make me a fluent speaker, but I hope I'll be able to do more than just smile when I meet people in Congo. Now, I need to go and water my Vocabulary!