Do you often feel lonely? What do you do when you feel that way? Hide yourself away and spend your time reading, watching TV or walking around?

You might think that feeling lonely is just like feeling happy, sad or scared — that it's just one of your various moods. That is true. However, if you let yourself be lonely for too long without dealing with it, you could be making a serious mistake.

    Doctors have known for some time that feeling lonely is bad for the mind. It can lead to mental health problems such as depression, stress and reduce confidence. “Being lonely means not feeling connected or cared for, but it's not about being mentally alone,” Lisa Jaremka, scientist from Ohio State University, US, told Live Science in January. And there's growing evidence that not having friends is connected with physical illness as well.

    In 2006, for example, scientists studied 2,800 women who had cancer. They found that those who had few friends or family were five times more likely to die of their disease than women with many social contacts. Also, even healthy people had a better chance of falling ill if they felt left out by others, according to the BBC.

    The results have scientists thinking that loneliness might hurt the immune system(免疫系统), which protects the body from diseases.

    Hoping to prove this theory, Jaremka and her research team put volunteers(志愿者) through a stress test. During the test, volunteers were asked to make an unprepared speech in front of a group of stony-faced people. The researchers found that volunteers who said they were lonely in their daily lives felt more stress during the test. And their blood samples showed that all the stress had managed to cause harmful changes to their immune system.

     “Loneliness has been thought of in many ways as a chronic stressor(慢性增压器) — a socially painful situation that can last for quite a long time, ” explained Jaremka, who led the study.

    The number of people suffering from loneliness is increasing all over the world. However, solving the problem is easier said than done. It won't work to just “tell anyone to go out and find someone to love you”, said Jaremka. “We need to create support networks.”

    The iPhone the iPad: each of Apple's products sounds cool and has become a fad(一时的风尚). Apple has cleverly taken advantage of the power of the letter “i”—and many other brands are following suit. The BBC's iPlayer—which allows Web users to watch TV programs on the Internet—used the title in 2008. A lovely bear—popular in the US and UK一that plays music and vide is called “iTeddy”. A slimmed-down version(简装本) of London's Independent newspaper was stated last week under the name “i”.

    In general, single-letter prefixes(前缀) have been popular since the 1990s, when terms such as e-mail and e-commerce first came into use.

    Most “i” products are targeted at young people and considering the major readers of Independent's “i”, it's no surprise that they've selected this fashionable name.

    But it's hard to see what's so special about the letter “i” Why not use “a”, “b”, or “c” instead? According to Tony Thorne, head of the Language Center at King's College, London, “i”works because its meaning has become ambiguous. When Apple uses “i”, no one knows whether it means Internet, information, individual or intcractive, Thorne told BBC Magazines. “Even when Apple created the iPod, it seems it didn't have one clear definition,” he says.

    “However, thanks to Apple, the term is now connected with portability.” adds Thorne.

    Clearly the letter “i” also agrees with the idea that the Western World is centered on the individual. Each person believes they have their own needs, and we love personalized products for this reason.

    Along with“Google” and “blog”, readers of BBC Magazines voted“i”as one of the top 20 words that have come to define the last decade.

    But as history shows, people grow tired of fads. From the 1900s to 1990s, products with “2000” in their names became fashionable as the year was connected with all things advanced and modern. How ever, as we entered the new century, the fashion disappeared.

    Climate change has had a number of effects on cities around the world, including rising see levels. And, this has become an especially big problem for coastal cities. City officials must now prepare for higher tides on their coasts. The American city of Miami is one example. Located in South Florida, Miami is home to nearly 3 million people and billions of dollars in land and buildings.

    Miami is one of the cities in America most at risk for rising sea levels. The waterfront is central to Miami's culture and economy. But as the seas rise with climate change .the water will not stay put. Large parts of South Florida are in danger of being under water in the coming years. Across Biscayne Bay, the City of Miami Beach is making improvements - raising streets, adding water pumps and more.

    It is costing the city a lot of money. Local communities will spend 500 million dollars for the improvements. Thankfully, the residents, the folks that are paying the bill for this work, realize that the cost of doing nothing is much greater. A possibility officials are discussing with residents is for city to buy homes in some places where flooding has been a problem. The city would then turn that land into parks of grassland that could hold the water.

    Over time, the city may need to take bigger risks. Miami's future depends largely on how much, and how fast, the oceans rise.

    Caroline Lewis leads the climate activism group, the CLEO Institute. She says cities cannot avoid the need to move inland. But, she says，a well-planned withdrawal (撤退) could include measures to keep people safely in place for as long as possible. And, she says, the world could learn from such a model. In these two Florida cities built on wetlands, there remains a lot of hopefulness.

    They are called "sea parrots", and sometimes "clowns (小丑) of the sea"!

    Atlantic puffins (海鹦) are small seabirds which are around 25 cm in length. They have black and white feathers and a large parrot-like beak (鸟喙). The beak changes color during the year. In winter, the beak has a dull gray color, but it turns orange in spring!

    Puffins spend most of their lives out at sea, resting on the waves when not swimming. They live on the eastern coast of Canada and the United States, and the western coast of Europe.

    Puffins live off small fish such as herring, hake and sand eels. Puffins flap (拍) their wings up to 400 times a minute and speeding through the air at up to 88 km an hour. Wow! What's more, puffins can dive down 60m under water in search of their favorite fish.

    In spring and summer, thousands of puffins stay together on the coasts and islands of the North Atlantic Ocean to start a puffin family. They usually pair up with the same partner as before some may have been together for 20 years! Puffins dig out a hole usually in a grassy bank. Both parents take it in turn to incubate (孵化) the egg for the next 36-45 days!

Although puffins are not classed as an endangered animal, their population in some places is becoming smaller. The main reasons are overfishing, which can lead to a shortage of food for puffins, and pollution—especially oil spills (溢出). Not only does the oil make these beautiful birds sick, it harms their feathers.

    The great-grandmother is learning English with the help of her family when she is at the age of 91. She hopes to use the language at next year's Olympic Games in Tokyo. Takamizawa was one of the more than 200, 00 people who requested to volunteer for Tokyo's 2020 Games. English is not required for service, but it is a useful skill for volunteers to have.

    But Takamizawa had not been able to learn the language when she was young. Takamizawa said that she was in high school when World War Two started. She said, "In my second year there, English was banned because it was the enemy language."

    Takamizawa said her grandchildren helped persuade her that she was not too old to learn. "When I talked to my grandchildren about my wish, they said, 'It's not too late. We will teach you one word a day' ". Natsuko is Takamizawa's granddaughter and main English teacher. Natsuko sends a new English word to her grandmother's phone every day. They also often work together directly on phrases that Takamizawa will need for the Olympics. "Welcome to Tokyo, this is the Olympic stadium, how can I help you?" Takamizawa answers when asked to say an English phrase she has learned. Natsuko explains that she wanted to give her grandmother something to enjoy. "I can clearly see her English is getting better. It's my joy now."

    The EF English Proficiency Index is a measure of the level of English spoken in a country. Japan ranks 49th among countries where English is not the first language. This situation is slowly changing as younger generations welcome English. However, Takamizawa believes real change will not happen unless Japanese people become more open to the rest of the world. With around 500 days to go until the games begin, the whole Takamizawa family is ready to welcome the world to Tokyo.

    Taking your pulse during physical activity allows you to measure how hard you are exercising. You should exercise to stay within your target heart range.

    Increasing your heart rate is a key part of exercise but it is important that your heart rate is not too high or too low. If you are a beginner, you should also be able to breathe comfortably while exercising. This will ensure that you are exercising at a level that is safe and effective for your body.

    The chart below illustrates target heart rate ranges for exercise based on the maximal heart rate for selected ages. Here are the steps for using the chart: