The sound of a mosquito can mean trouble in many parts of the world. The bite of the mosquito can be deadly. The insects carry serious diseases like malaria (疟疾). It is estimated that almost 630,000 people died from malaria and malaria­related causes in 2012, and most of these cases were in African countries.

    In the United States, a group of California scientists are working to develop a more effective and less costly substance (物质) to protect people from mosquitoes. The researchers are investigating the sense of smell in mosquitoes. They found the insects use the same receptor for identifying carbon dioxide in human breath as they do for the smell of our skin. Anandasankar Ray, who is leading the investigation, says scientists tested more than a million chemical compounds (化合物) until they found a substance called Ethyl Pyruvate. He says Ethyl Pyruvate makes the mosquitoes' receptors inactive. “When we apply Ethyl Pyruvate to a human arm and offer it to hungry mosquitoes in a cage, very few of the mosquitoes are attracted to the human arm because only a few of them are able to smell it out,” said Ray.

    Genevieve Tauxe, a member of the research team, says it was not easy to find the neurons (神经元) of noble cells that recognize both the smell of human breath and skin. “With the device used to examine the mosquito, we are able to insert a very small electrode (电极) into the part of the mosquito's nose, where its smelling neurons are and where the smell is happening,” said Tauxe.

    Anandasankar Ray says a product based on Ethyl Pyruvate may cost less to produce than DEFT, the most effective chemical treatment now in use. He says DEFT is too costly for most people who live in areas affected by malaria.

    “Perhaps by finding smells that can attack other target receptors, we will be able to improve upon DEFT and finally have the next generation of insect behaviour control products,” said Ray.

    If you want to become a fluent English speaker, you should take some advice: there are four skills in learning English. They are listening, speaking, reading and writing. The most important thing you must remember is that if you want to improve your speaking and writing skills you should first master the skills of reading and listening.

    Read as much as you can. But your reading must be active. It means that you must think about the meaning of the sentences, the meaning of the unfamiliar words, etc.

    There is no need for you to pay much attention to grammar—or try to understand all the unfamiliar words you come across, but the fact you see them for the first time and recognize them whenever you see them, for example in other passages or books, is enough. It would be better to prepare yourself a notebook so you can write down the important words or sentences in it.

    As for listening, there are two choices: besides reading, you can listen every day for about 30 minutes. You can only pay attention to your reading and become skillful at your reading, then you can catch up on your listening. Since you have lots of inputs(输入) in your mind, you can easily guess what the speaker is going to say. This never means that you should not practice listening.

    For listening you can listen to cartoons or some movies that are specially made for children. Their languages are easy. Or if you are good at listening, you can listen to VOA or BBC programs every day. Again the thing to remember is being active in listening and preferably(更好地) taking some notes.

    If you follow these pieces of advice, your speaking and writing will improve automatically(自动地)，and you can be sure that with a little effort they will become perfect.

    Imagine waking up one day and finding that your beautiful local beach is no more—gone, its fine white sand swept away by an abnormal storm. You go about your daily business for 12 long years and then suddenly the beach is back, all its glory restored by another storm. This is what happened on the island of Achill, off the coast of Ireland, where people are celebrating the return of the beautiful Ashleam Bay beach that was taken from them in 2005.

    That in itself is unusual enough, but the story gets even better! You see, another beach in Achill did a disappearing act once, but took much longer to return. The beach at Doonagh, located only six miles away from Ashleam Bay, was restored earlier in 2016 after waves created by spring storms had swept away all the sand in 1984, leaving just rock pools behind.

    There is local legend that stretches back hundreds of years that says this beach at Ashlcam Bay returns for a short every seven years then disappears again. But this time around it took a bit longer than that. It was last seen in 2005 and it stayed for a few months at that time before it was washed away again.

    As you can imagine, everyone on the island of Achill is thrilled to have their sandy beach back, and even though no one knows how long it's going to be around for, they are making the most of the time they've got before it disappears again.

    Some may be quick to believe climate changes cause the phenomenon, but that's not the reason these two beaches in Achill keep disappearing, Dr Kevin Lynch, a geographer at NUT Galway, says that these occurrences are the result of hydrodynamics (流体力学) and sediment(沉积物) supply, rather than climate changes.

    Regardless of what's causing them, disappearing and reappearing beaches are just part of what makes nature so fascinating.

    You know the feeling that you have left your phone at home and feel anxious, as if you have lost your connection to the world. “Nomophobia” (无手机恐惧症) affects teenagers and adults alike. You can even do an online test to see if you have it. Last week, researchers from Hong Kong warned that nomophobia is infecting everyone. Their study found that people who use their phones to store, share and access personal memories suffer most. When users were asked to describe how they felt about their phones, words such as “hurt” (neck pain was often reported) and “alone” predicted higher levels of nomophobia.

    “The findings of our study suggest that users regard smartphones as their extended selves and get attached to the devices,” said Dr. Kim Ki Joon. “People experience feelings of anxiety and unpleasantness when separated from their phones.” Meanwhile, an American study shows that smartphone separation can lead to an increase in heart rate and blood pressure.

    So can being without your phone really give you separation anxiety? Professor Mark Griffiths, psychologist and director of the International Gaming Research Unit at Nottingham Trent University, says it is what is on the phone that counts-the social networking that creates Fomo (fear of missing out).

    “We are talking about an internet-connected device that allows people to deal with lots of aspects of their lives,” says Griffiths. “You would have to surgically remove a phone from a teenager because their whole life is rooted in this device.”

Griffiths thinks attachment theory, where we develop emotional dependency on the phone because it holds details of our lives, is a small part of nomophobia. For “screenagers”, it is Fomo that creates the most separation anxiety. If they can't see what's happening on Snapchat or Instagram, they become panic-stricken about not knowing what's going on socially. “But they adapt very quickly if you take them on holiday and there's no internet,” says Griffiths.

    If you also have a friend like Francia Raisa, you are really lucky. On Thursday, singer and actress Selena Gomez, 25, used Instagram(照片墙,一款社交软件) to explain why she was "laying low" this summer. She posted a photo of herself in a hospital bed with her friend Francia Raisa holding hands. She said she recently received a kidney transplant(肾脏移植) from her best friend because of complications(并发症) from lupus(狼疮), an autoimmune disease, which means it is the result of the immune system attacking normal tissue, including the kidneys, brain, heart and lungs.

    People with lupus may first experience tiredness, joint pain or a little bit of rash(皮疹) on their bodies and can go for a long time before their doctors realize it is more serious. Many people see two or four doctors before the real problem is picked up. According to Dr. Kyriakos Kirou, roughly a third to one­half of people with lupus develop kidney disease, and up to one in five of them will eventually need a transplant, sometimes because they weren't treated with effective drugs to prevent the immune system from attacking the kidneys. Though Gomez said that she was "very well now," she warned about the dangers of not taking medical diagnoses(医学诊断) seriously, like she did before.

    Her Instagram post also called attention to two major health topics: the need for living organ donators and the fact that Gomez represents three groups more likely to be diagnosed with lupus and lupus­related kidney disease. Nine out of 10 people diagnosed with lupus are women, and most develop the disease between the ages of 15 to 44. And lupus is two to three times more common among women of color, including Hispanic (西班牙裔)women, according to the Lupus Foundation.

    Raisa is Latin(拉丁人), and Gomez's father is of Mexican origin. While it's not essential that the organ donator and receiver be of the same race, people who share a similar racial background sometimes are better matched, according to data from the United Network for Organ Sharing.

    Donald Watson was a man who thought very much about the food he ate. He was born in Yorkshire, England, in September 1910. And he died in November 2005, at the age of 95. That is a very great age. Watson explained that it was because he never ate any food from animals.

    When he was a boy, Watson stayed on a farm. .He loved to see the animals. He said that they gave so much to people. And all the animals were so friendly. Then, one day, he saw a man killing a pig. He was very sad. From then on, Watson decided that he would never again eat meat. Twenty years later he decided that he wouldn't eat anything from animals, such as milk, cheese or eggs. He became vegan (素食主义者).

    Watson formed a group called "The Vegan Society". In its newspaper, The Vegan Society thought it was terrible and wrong to eat food from animals. At first, there were not many people who agreed with him. They thought it was crazy to do it. Most people thought it was too difficult and unhealthy. However, over time, more and more people began to agree with Watson and The Vegan Society.

    People become vegans for many reasons. Watson and his friend stopped eating because they loved animals. They believed that it was wrong to hurt another living thing.

    Now, people also become vegans for environmental reasons. Keeping animals takes a lot of resources(资源), including water and food. Also, in some places, people are cutting down trees to create more land for cows. By avoiding food from animals, vegans hope to protect these forest areas.

    Finally, just like Watson, some people believe that being a vegan is healthier. They believe that food from animals causes heart problems, a high body weight and many other health problems.