There is an English saying that “Laughter is the best medicine.” Until recently, few people took the saying seriously. Now however, doctors have begun to look into laughter and the effects it has on the human body. They have found that laughter can really improve people's health.

    Tests were carried out to study the effects of laughter on the body. People watched funny films while doctors checked their hearts, blood pressure, breathing and muscles. It was found that laughter has similar effects to physical exercise. It increases blood pressure, makes the heart beat quicker and makes people breathe deeper; it also works on several groups of muscles in the face, the stomach, and even the feet. If laughter exercises the body, it must be beneficial.

    Other tests have shown that laughter appears to be able to reduce the effects of pain on the body. In one experiment doctors produced pain in groups of students who listened to different radio programs. The group that tolerated（忍耐）the pain for the longest time was the group which listened to a funny program. The reason why laughter can reduce pain seems to be that it helps to produce a kind of chemical in the brain which diminishes both stress and pain.

    As a result of these discoveries, some doctors in the United States now hold laughter clinics, in which they help to improve their patients' condition by encouraging them to laugh. They have found that even if their patients do not really feel like laughing, making them smile is enough to produce beneficial effects similar to those caused by laughter.

    Many animals recognize their food because they see it.So do humans.When you see an apple or a piece of chocolate you know that these are things you can eat.You can also use other senses when you choose your food.You may like it because if smells good or because it tastes good.You may dislike sonic types of food because they do not look,smell or taste very nice.Different animals use different senses to find and choose their food.A few animals depend on only one or their senses,while most animals use more than one sense.

    Although there are many different types of food,some animals spend their lives eating only one type.The giant panda eats only one particular type of bamboo.Other animals eat only one type of food even when given the choice. A kind of white butterfly will stay on the leaves of a cabbage,even though there are plenty of other vegetables in the garden.However,most animals have a more varied diet.The bear eats fruits and fish.The fox eats small animals,birds and fruits.The diet of these animals will be different depending on the season.

    Humans have a very varied（广泛的）diet.We often eat food because we like it and not because it is good for us. In countries such as France and Britain,people eat foods with too much sugar.This makes them overweight,which is bad for their health.Eating too much red meat and animal products,such as butter,can also be bad for the health. Choosing the right food,therefore,has become an area of study in modern life.

Protect Children from Cyber-bullying

    When you think about bullying, you might think of a child being bullied by another in the schoolyard. As more young people have access to computers and cell phones, traditional bullying has gone digital, which has not yet gained awareness in Chinese parents.

    Cyber-bullying, first invented by Canadian educator Bill Belsey, is the use of the Internet and related technologies to harm other people, in an intentional, repeated, and unfriendly manner. It involves threatening text messages, the spread of online rumors on social networking sites, and intentionally keeping someone out of an online group. Cyber-bullying is at an all-time high in the US. According to a study from the US Department of Justice, more than 43% of teenagers report being victims（受害者）of cyber-bullying.

    Compared to face-to-face bullying, cyber-bullying is considered to have a worse emotional effect on the victims, and kids could feel more desperate and depressed. Severe, long-term or frequent cyber-bullying can leave victims at greater risk for anxiety, depression, and other disorders. Research says that cyber-bullying victims were almost twice as likely to have attempted suicide compared to youths who had not experienced it.

In traditional schoolyard bullying, at least home is a safe place for the victims. But cyber-bullying is endless—it could happen anytime. Moreover, in the digital world, bullying is much easier, as a bully can pick on people with a much lower risk of being caught.

    Actually, cyber-bullying has become a worldwide issue. In the US, as several teens committed suicide because of cyber-bullying, some schools set rules to punish cyberbullies. Laws to punish cyber-bullying have been introduced in some states. In China, cyber-bullying is still considered by many parents and educators as a problem that involves physical contact. However, as cell phones and laptops are becoming common equipment for teenagers, social interactions have increasingly moved from personal contact to virtual contact. Cyber-bullying is spreading faster than expected.

    For schools and parents, safety rules should be set in the virtual world for kids, such as telling them not to let out anything to a stranger. Active steps should be taken to make the public aware of the seriousness of this problem, because it would be too late to take measures after tragedy strikes.

The Cost of Higher Education

    Individuals (个人) should pay for their higher education.

    In general, a university education is of huge and direct benefit to the individual. Whether they are majoring in geography, geometry or any other subject, graduates earn more than non-graduates. Meanwhile, social mobility is ever more dependent on having a degree. However, only some people have it. So the individual, not the taxpayers should pay for it. There are pressing calls on the resources (资源) of the government. Using taxpayers' money to help small number of people to earn high incomes in the future is not one of them.

    Full government funding (资助) is not very good for universities. Adam Smith worked in a Scottish university whose teachers lived off student fees. He knew and looked down upon 18th-century Oxford, the grand university having much glory, where the academics lived comfortably off the income received from the government. Guaranteed salaries, Smith argued, were the enemy of hard work and when the academics were lazy and incompetent, the students grew similarly lazy in a gradual way.

    If students have to pay for their education, I guess they not only work harder, but also demand more from their teachers and have a better grasp of the subjects. And their teachers have to keep them satisfied. If that means taking teaching seriously, and giving less time to their own research interests, that is surely something to celebrate.

    Many people believe that higher education should be free because it is good for the economy (经济). Many graduates clearly do contribute to national wealth, but so do all the businesses that invest (投资) and create jobs. If you believe that the government should be generous enough to pay for higher education because graduates are economically productive, you should also believe that the government should pay part of business costs. Anyone promising to create jobs should receive a gift of capital（资金） from the government to invest.

    Therefore, it is the individual, not the government who should pay for their university education.

    Around this time a few years ago, it was common to see videos of friends on social media having a bucket of icy water thrown on them. Known as the “ice bucket challenge”, it was created as a way to raise money for the medical condition ALS. But now, there's a new challenge and this time, no water is involved.

    What is it? Well, think of a fruit that you'd never normally sink your teeth into. Perhaps you've got it: a lemon. While we enjoy using lemons to add flavor to dishes, very few of us would actually eat one as we'd eat an apple or an orange.

    But the horrible taste is the precise reason why the “lemon face challenge” is taking off. Participants bite into a lemon, taking a selfie as they do it before posting the photo online. The fun is all about expression people make as all that citric acid (柠檬酸) hits their taste buds (味蕾). Every expression seems to say, “This is worse than freezing water.”

    The serious side to this trend is the good cause it's all in aid of. The challenge aims to raise awareness of a rare brain cancer that affects young children. It was started by Aubregh Nicholas, an 11-year-old US kid. She was diagnosed with this rare brain cancer herself in September 2017, but has since raised almost $50000 to cover her medical expenses thanks to the challenge.

    If a challenge is going to raise publicity and contributions from people, it has to be something interesting and original. That way the ice bucket challenge took off in 2014 and it explains why so many people are now sharing their lemon faces. There are a lot of stories about the downside of social media these days. The charity challenges, however, show how online culture can unite the world and bring help to the people who most need it.

    People like to post their selfies(自拍照) on social media. To know more about it, scientists at Syracuse University in New York recently did a research and came up with some surprising findings.

    People who post selfies and use editing software to make themselves look better show behavior connected to narcissism(自恋), the researchers said. Makana Chock, a professor from Syracuse University, said because social media is mostly used by people to share unimportant information about their lives, it is a good place for people to "work towards satisfying their own vanity." Those "likes" under their Facebook selfies make them feel good.

    Besides, people who post group selfies show a need for popularity and a need to belong to a group, the research found. Some people feel "peer(同伴) pressure" to post selfies and some follow the popular belief that if there is no picture of an event or experience, it did not really happen. "Anyway, it shouldn't be seen as negative. People get sense of satisfaction especially when they get likes. And it does no harm," Chock said.

    Other findings from the study include: There are no major differences on how often men and women post selfies and how often they use editing software. But men who post selfies showed more of a need to be seen as popular than women who posted selfies.

Chock said posting selfies on social media is not all that different from what people have done for many years. On trips and special events, our parents and grandparents used cameras instead of phones to take photos. They would bring back photos to show friends and family. You had no choice but to look at them. You probably commented about how nice everyone in the photos looked, especially children and the person showing the photos. They were happy to hear your comments. That was the old way of "clicking like". On social media, however, people can decide not to look at photos — even if they click "like".