Mosquitoes have an extraordinary ability to find humans far away and fly straight to their skin. Mosquitoes can do more than cause an itchy (发痒的）wound. Some mosquitoes spread several serious diseases, including Dengue, yellow fever and malaria.

    Over one million people worldwide die from these diseases each year. New research now shows how mosquitoes choose who to bite.

    Mosquitoes need blood to survive. They are attracted to human skin and breath. They smell the carbon dioxide gas, which all mammals breathe out. This gas is the main way for mosquitoes to know that a warm-blooded creature is nearby.

    But mosquitoes also use their eyes and sense of touch. Michael Dickinson is a professor at the California Institute of Technology. His research shows how these small insects, with even smaller brains, use three senses to find a blood meal.

    Michael Dickinson's team used plumes—a material that rises into the air of carbon dioxide gas into a wind tunnel (隧道). They then used cameras to record the mosquitoes. The insects followed the plume.

    Then, the scientists placed dark objects on the lighter colored floor and walls of the tunnel. Mr. Dickinson said, at first, the mosquitoes showed no interest in the objects at all. “What was quite surprising is that the mosquitoes fly back and forth for hours. These are hungry females and they completely ignore the objects on the floor and wall of the tunnel. But the moment they get a hit of CO₂, they change their behavior quite obviously and now would become attracted to these little visual blobs (斑点).”

    This suggested to the researchers that a mosquito's sense of smell is more important in the search for food. Once mosquitoes catch a smell of a human or animal, they also follow visual signals.

    Next time a customer comes to your office, offer him a cup of coffee. And when you're doing your holiday shopping online, make sure you're holding a large glass of iced tea. The physical sensation (感觉) of warmth encourages emotional (情感的) warmth, while a cold drink in hand prevents you from making unwise decisions—those are the practical lesson being drawn from recent research by psychologist (心理学家) John A. Bargh.

    Psychologists have known that one person's perception (感知) of another's “warmth” is a powerful determiner in social relationships. Judging someone to be either “warm” or “cold” is a primary consideration, even trumping evidence that a “cold” person may be more capable (能干的). Much of this is rooted in very early childhood experiences, Bargh argues, when babies' sense of the world around them is shaped by physical sensations, particularly warmth and coldness.

    Feelings of “warmth” and “coldness” in social judgments appear to be universal. Although no worldwide study has been done, Bargh says that describing people as “warm” or “cold” is common to many cultures, and studies have found those perceptions influence judgment in dozens of countries.

    To test the relationship between physical and psychological warmth, Bargh conducted an experiment which involved 41 college students. A research assistant who was unaware of the study's hypotheses (假设), handed the students either a hot cup of coffee, or a cold drink, to hold while the researcher filled out a short information form: The drink was then handed back. After that, the students were asked to rate the personality of “Person A” based on a particular description. Those who had briefly held the warm drink regarded Person A as warmer than those who had held the iced drink.

    “We are grounded in our physical experiences even when we think abstractly (抽象的),” says Bargh.

    Songs that make our hearts happy can make them stronger too, US researchers reported on Tuesday.

    They found that when people listened to their favorite music, their blood vessels (血管) dilated in much the same way as when they are laughing, or taking blood medications.

    “We have a pretty impressive effect,” said Dr Michael Miller, director of preventive cardiology (心脏病学) at the University of Maryland Medical Center in Baltimore.

    “Blood vessel diameter improved,” he said.“The vessel opened up pretty significantly. You can see the vessels opening up with other activities such as exercise.” A similar effect is seen with drugs such as statins.

    When blood vessels open up more, blood flows more smoothly and is less likely to form the clots (凝块) that cause heart attacks and strokes. “We are not saying to stop your statins or not to exercise but rather to add this to an overall program of heart health,” said Miller, who presented his findings to a meeting of the American Heart Association in New Orleans.

    Miller's team tested 10 healthy, non-smoking men and women, who were told to bring their favorite music.They spent half an hour listening to the recordings and half an hour listening to music they said made them feel anxious while the researchers did ultrasound tests designed to show blood vessel function.

    Compared to their normal baseline measurements, blood vessel diameter increased 26 percent on average when the volunteers heard their joyful music.Listening to music they disliked — in most cases in this group — blood vessels narrowed by six percent, Miller said.

    Miller said he came up with the idea after discovering that laughter caused blood to literally flow more smoothly. “I asked myself what other things make us feel really good, besides calories from dark chocolate of course.Music came to mind. It makes me feel really good,” he said.

    Most of the volunteers chose country music but Miller said the style is not so important rather than what pleases each individual.

    A “Gap Year” is a period of time when a student takes a break before going to university. It is often spent travelling or working. It can give young people useful learning experiences and new skills.

    Gap years are popular with European and Australian students, but remain less popular in America. However, in recent years, more and more American students are preparing for college by taking a gap year. The advantages of taking a gap year are as follows：

Learn about the World and Yourself

    Although you don't have to go abroad to experience gap years, most gap year students catch the chance to travel abroad. You are able to work out who you are and what you are for. The experiences of different cultures offer you interesting lessons. You can learn more about the world and get to know yourself better.

 Face Challenges and Have Fun

    A gap year is not only a time to take a vacation, but also a time to face challenges. Gap year students usually work, volunteer or take service projects. You have to learn how to get along in the real world. This process isn't always easy, but it is an important part of growing up. Only in this way can you enjoy life and have fun.

Save Money and Improve Your College Admission Chances

    There's a common thought that gap years are only for rich students, but it's not true. Actually, taking a gap year can save your money. Gap year students often take a part-time job. Besides, at the end of a gap year, students are much more likely to know what to study in college. Clear learning goals ran keep the students working hard instead of wasting time and money playing.

    Imagine an admission officer trying to admit (录取) only one between two students. Both of them are excellent and have high grades. However, one student has much practical experience or has volunteered in his vacation. Who do you think the admission officer will choose?

    Chewing gum(口香糖) has its origins in ancient times from Mayans to Greeks who would chew the resin(树脂)of certain trees for medical purposes and maybe even for freshening breath. The history of chewing gum continued as Native Americans introduced it to European settlers.

    Chewing gum hit the market after Santa Anna brought a case of chicle(糖胶树脂) from Mexico to New York. Santa Anna gave some to the part-time inventor Thomas Adams Thomas Adams changed the gum and marketed it as a candy. The invention took off and was known as Chiclets.

    In 1900 Frank Fleer coate chewing gum with sugar, and in 1906 Blibber Blubber was invented, but never made it to market. Blibber Blubber was too sticky and it was also too difficult to remove the burst bubble(破了的泡泡) from one's skin without using some special tools.

    A history of bubblegum just wouldn't be complete without mentioning the gumball machine, which popularized gum. The first gumball machine came onto the scene in 1907 and sold sugar-coated chewing gum.

    However, it wasn't until 1928 that bubblegum was created. Walter Diemer, working for Frank Fleer's gum company, discovered bubblegum by accident while experimenting in the lab during his breaks. The gum was named Dubble Bubble. Pink was the only color which could be used at the time, and Dubble Bubble has remained pink ever since.

    According to the International Chewing Gum Association,during WWII Dubble Bubble was handed out by US military members as gifts, thereby spreading its popularity among the peoples of Europe, Africa, and Asia. And in the 1930s he first bubblegum cards appeared. "the pictures changed from war heroes to Wild West figures to professional athletes."

    Bubblegum has been popular ever since, especially among children, thanks to its inventive shapes, and sugary flavors, from original bubblegum to a yardstick of fruity bubblegum.

Norwegians would perhaps highlight their custom of "gå på tur"— going on a journey on foot or on skis. In Denmark, everyone knows what "hygge" is — to freely enjoy the good life with the people you love. They're the issues of "intangible cultural heritage", things that cannot be physically touched such as traditions, stories, music, dance and craft skills.

In 2003, UNESCO, the education, science and culture organization of the United Nations, adopted an agreement to "preserve the intangible" and many developing-world countries were quick to get their traditions included on the official list. But it would take almost 10 years for "Agreement for the Safeguarding of the Intangible Cultural Heritage" to be approved by the Scandinavian countries.

Annika Sjöberg is responsible for managing the work of the agency in Sweden. She has been, and continues to be, flooded with suggestions of intangible cultural heritage worthy of protection, submitted by committed citizens and organizations wanting to see their particular traditions included on the list that should be ready sometime in the next couple of years.

Suggestions have also been received concerning various maritime traditions: old shipwright skills such as the building of wooden hulled vessels, are in decline and at risk of being lost forever.

"Our work has attracted considerable attention as it is regarded as being a little out in left field," says Sjöberg. "In addition, it's also opened people's eyes to the fact that the things we can't physically touch indeed have a major bearing on the way in which we live. Even in an urbanized society, there is knowledge we carry with us that we've inherited from previous generations-knowledge that's important to preserve and take care of."

Sjöberg explains that the point is not to preserve this cultural heritage in a stony rigid form, as traditions must be allowed to change and evolve. She also emphasizes that her work should not be interpreted as a nationalistic project, rather as a means of multicultural spreading.

It's actually a matter of documenting the knowledge that exists in the various traditions. What is most exciting is the diversity that now exists and the ways in which different cultures interact with each other.