A rainforest is an area covered by tall trees with the total high rainfall spreading quite equally through the year and the temperature rarely dipping below 16℃. Rainforests have a great effect on the world environment because they can take in heat from the sun and adjust the climate. Without the forest cover，these areas would reflect more heat into the atmosphere, warming the rest of the world. Losing the rainforests may also influence wind and rainfall patterns，potentially causing certain natural disasters all over the world.

    In the past hundred years，humans have begun destroying rainforests in search of three major resources（资源）: land for crops，wood for paper and other products，land for raising farm animals. This action affects the environment as a whole. For example，a lot of carbon dioxide（二氧化碳）in the air comes from burning the rainforests. People obviously have a need for the resources we gain from cutting trees but we will suffer much more than we will benefit.

    There are two main reasons for this. Firstly，when people cut down trees，generally they can only use the land for a year or two. Secondly，cutting large sections of rainforests may provide a good supply of wood right now，but in the long run it actually reduces the world's wood supply.

    Rainforests are often called the world's drug store. More than 25％ of the medicines we use today come from plants in rainforests. However，fewer than 1％of rainforest plants have been examined for their medical value. It is extremely likely that our best chance to cure diseases lies somewhere in the world's shrinking (萎缩的) rainforests.

    If you see a group of people dancing and singing on the street or in the railway station, you don't need to feel surprised. They are a flash mob(快闪族), which is a group of people who come together suddenly in a public place, do something unusual for a brief period of time, and then quickly break up. They are usually organized with the help of the Internet or other digital communication network. At a predetermined(预先决定的) time, they gather and perform some distractions(消遣) such as waving their hands and exchanging books. Then, they quickly break up before the police can arrive. Using mobile phones, the flash mob can change its location if the first one has been replaced for any reason.

    Bill Lasik, senior editor of Harper's Magazine, organized the first flash mob in Manhattan in May 2003 and the first successful flash mob came together on June 3, 2003 —after the first attempt failed at Macy's department store. Lasik claimed that the activity was designed to make fun of hipsters(赶时髦的人), and call attention to the cultural atmosphere.

    Flash mob gatherings can sometimes shock people. Such an activity might seem amusing and untrue, but it also might frighten people who are not aware of what is taking place. Undoubtedly, flash mobs can serve as good political tools in any direction. They also have great economic potential, such as using flash mobs to advertise a product.

    The flash mob is now becoming more and more popular. People use it to do many things. For example, in 2009, Michael Jackson's fans took part in a flash mob to remember him. Hundreds of his fans gathered singing and dancing Michael's famous song “Beat It” together. Flash mobs give people from all walks of life an opportunity to come together to create a memory.

    A disease called “Panama” is threatening supplies of the world's most popular fruit—banana.Two years ago,the United Nations warned that the "Panama disease" could destroy "much of the world's banana crop."Since then,things have not gotten better.A new outbreak was discovered last year in Australia.The disease started in Asia in the 1990s, and later spread to Africa and the Middle East.

    World health officials worry the disease could travel to Latin America,one of the top banana producers in the world.All this is a big concern because bananas are an important source of income and nutrients for millions of people.They are grown in 135 tropical nations.The United Nations lists bananas as one of the most important foods, along with rice,wheat and corn.

    Randy Ploetz is a professor at the Tropical Research & Educational Center at the University of Florida.Many consider him as America's top banana expert.As he explained,Panama disease affects the Cavendish banana.The Cavendish is one of more than 500 kinds of bananas.But it is the most popular.

    “The industry is waking up to the problem,”Ploetz said.“They are pretty scared.”He was speaking Thursday by telephone from Miami,Florida,where he is among 1,000 people attending the International Banana Congress.The meeting was supposed to take place in Costa Rica,but was moved at the last minute.There were concerns banana growers could spread Panama disease from dirt collected on their shoes,Ploetz said.

    Ploetz said reports that Cavendish banana production could end are not correct.But if the disease spreads to Latin America,it could hurt the world's economy along with food supplies for millions of people.Still,he said there is reason for hope.Scientists in Australia are working on a genetically engineered banana that might not be at risk of getting Panama disease.

    Some places in the world have strange laws. It's important for you to know about them before going there.

    Whoever likes to chew gum(口香糖) may have to leave Singapore. The government really wants to keep the city clean and will fine you for chewing gum.

     Before you leave for the United Arab Emirates you'd better make sure you aren't visiting during Ramadan(斋月). During that time you aren't allowed to eat or drink in public. Tourists have been fined up to $275 for drinking in public.

    Lovers spend so much time kissing each other goodbye at train stations that trains often start late. This law— no kissing your lover goodbye at train stations – is rather old, and isn't in use today in France.

In Thailand it's against the law to drive a car or motorcycle without a shirt on, no matter how hot it is. Punishments are different in different areas and can include warnings and tickets costing about $10. No joke — the local police will stop you.

     Studies in Denmark have shown that cars with their headlights on are more noticeable by other drivers than those with their headlights off. Drivers there are required to leave their headlights on even during the day, or they may face a fine up to $100.

    Do you often buy things using coins? Don't do it in Canada. The Currency Law of 1985 doesn't allow using only coins to buy things. Even the use of the dollar-coin is limited (受限制的). The shop owner has the right to choose whether to take your coins or not.

    Make sure you know about these laws before your next trip. Better safe than sorry.

    Nowadays women appear to have a positive image of themselves as safer drivers than men.

    In a survey done for insurer MetLife, 51% of women said they drive more safely. The evidence is on their side: Men are 3.4 times more likely than women to get a ticket for careless driving and 3.1 times as likely to be punished for drunk driving. "Women are on average less aggressive and more law abiding (守法的) drivers, which leads to fewer accidents," the report says. However, not all male drivers share the same opinion. Of the men surveyed by MetLife, 39% claimed male drivers were safer. The findings did back them upon one point: automotive knowledge. The report showed that more men are familiar with current safety equipment such as electronic stability control, which helps prevent rollover accidents.

    Auto safety unavoidably matters to Money. Insurance companies focus on what classes of drivers have the lowest dollar amounts of claims, and for now, that mainly includes women. In general, women pay about 9% less for auto insurance than men. A study by the website also showed that auto insurance rates are lower for women in most states. Among individual states, women get the greatest, advantage in Wyoming (where they pay 20% less), South Dakota and Washington, D. C, where their insurance costs are 16% lower.

    "More than 11,900 male drivers died in US traffic accidents in 2009, compared with just under 4,900 women drivers" according to the study. "Based on miles traveled, men died at a rate of 2. 5 deaths per 100 million miles traveled, vs. 1.7 deaths for women."

    As Simon Kindleysides, 34, took his first step in the London Marathon in April, he felt as if magic was in the air.

    "As we were walking toward the first mile, we actually started joining all the runners," he said. "Everyone was on the streets, cheering, and that was a magical moment." As time went on, the crowds and other racers spread around. Kindleysides and his team of eight supporters continued walking.

    Kindleysides, who is paralyzed(瘫痪的)from the waist down and typically uses a wheelchair, was equipped with an exoskeleton(体外骨骼)to help him walk. His supporters walked with him to change the batteries in his exoskeleton so he could keep moving.

    In 2013, Kindleysides was diagnosed with a brain tumor (肿瘤) that was growing in a way that pressed on certain nerves, leading to him losing feeling in his legs. He was told he would never walk again. Before his paralysis, the London­based singer and dancer had "always wanted to run a marathon," he said, but he never made the plan to do so­­until this year.

    During the London Marathon, the last two miles were the hardest. "At that point, I was exhausted. It was freezing cold, and I was hurting emotionally," Kindleysides said. But he kept going. "I didn't want to let people down. I had a team of eight, and I was raising money for The Brain Tumour Charity," he said. "I didn't want to let them down, myself down, and I thought if I would get this far, I would have to continue."So he continued and made history as the first paralyzed man to complete the London Marathon on foot.

    Then, recovering at home, he shared his accomplishment with his three children. "They used to say I'm the only dad in their whole school who's in a wheelchair, and now they say I'm their dad, the only one who has walked a marathon," he said.

    Kindleysides is training to complete three more marathons next year, including the London Marathon again.