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.

    This could be Micah Fitz, first spring without football practices. The 14-year-old has been playing since he was 3, but because he's home-schooled, he can't try out for the local team at Patriot High School in Prince William County, Virginia.

    “I can't play this half of the year and my friends are going to be playing five or six times a week,” he said. “They're going to be getting better and stronger playing with kids that are good.”

Micah and his family—along with many other home-schooling families across Virginia—are hoping the Virginia General Assemble will approve a bill this year that would allow kids like him to try out for sports on public school athletic teams. The bill, called the “Tebow bill”, is named after football player Tim Tebow, who was home-schooled but was allowed to play on a high school team before going to the University of Florida, where he led his team to two national championships.

    Many major statewide education organizations said the bill wouldn't be fair to public school students. Ken Tilley, the executive director of the Virginia High School League, said the bill would violate two of the league's most long-standing standards for qualification: enrollment (注册入学) and academic standing.

    Home-school advocates argue that they are required by the law to document academic progress. But many opponents say students always have the option of attending public high school. That might be what Sydney Bowman, a 12-year-old from Luchetts, will do to keep wrestling, although she would prefer to continue to be taught at home. In her case, girls' wrestling teams are rare enough that there aren't many options other than public school.

    But Micah' mom, Terri Fits, a former public school teacher, said that although they support the local schools and love to cheer on the teams, they like the flexibility of home-schooling.

    Every person has their own way of saying things, their own special expressions. Many everyday American expression are based on colors.

    Red is a hot colour. Americans often use it to express heat. They may say they are red hot about something unfair. When they are red hot they are very angry about something. The small hot tasting peppers found in many Mexican foods are called red hots for their colour and their fiery taste. Fast loud music is popular with many people. They may say the music is popular with many people. They may say the music is red hot, especially the kind called Dixicland jazz.

    Pink is a lighter kind of red. People sometimes say they're in the pink when they're in good health. The expression was first used in America at the beginning of the 20th century. It probably came from many babies who were born with a nice pink colour showing good health.

Blue is a cool colour. The traditional blues music in t he United States is the opposite of red hot music. Blues is slow, sad and soulful. Duke Ellington and his orchestra recorded a famous song—Mood Indigo—about the deep blue colour, indigo. In the words of the song: “You aren't blue till you've had that Mood Indigo.” Someone who is blue is very sad.

    The colour green is natural for trees and grass. But it is an unnatural colour for humans. A person who has a sick feeling in his stomach may say he feels a little green. A passenger on a boat who is feeling very sick from high waves may look very green.

    Sometimes a person may be upset because he does not have something as nice as his friend's, like a fast new car. That person may say he is green with envy. Some people are green with envy because a friend has more dollars of greenbacks. Dollars are called greenbacks because that is the colour of the back side of the paper money.

    The colour black is often used in expressions. People describe a day in which everything goes wrong as a black day. The date of a major tragedy is remembered as a black day. a blacklist is illegal now. But at one time, some businesses refused to employ people who were on a blacklist for belonging to unpopular organizations.

    The ninth week of SEAL(Sea, Air, Land) training is referred to as Hell Week. It is six days of no sleep, physical and mental suffering and one special day at the Mud Flats (泥沼）where you will sink into the mud.

    It is on Wednesday of Hell Week that we came down to the mud flats and spend the next 15 hours trying to survive the freezing-cold mud, the cold wind and the strong pressure from the instructors to give up.

    As the sun began to set that Wednesday evening, my training class, having broken some of the rules, was ordered into the mud. We sank into the mud until only our heads could be seen. The instructors told us we could leave the mud if only five men would give up—just five men and we could get out of the cold.

    Looking around the mud flat, it was clear that some of us were about to give up. It was still over eight hours till the sun came up--eight more hours of coldness. Our cries were so loud that it was hard to hear anything. And then, one voice began to fly through the night--one voice raised in song.

    The song sounded terrible, but it was sung with great power. One voice became two, and two became three, and before long everyone in the class was singing.

    We knew that if one man could rise above the suffering then others could as well. The instructors warned us of more time in the mud if we kept up the singing—but the singing went on and on. And somehow, the mud seemed a little warmer, the wind a little weaker and the morning not so far away.

    If I have learned anything in my time traveling the world, it is the power of hope. The power can change the world by giving people hope.

    So, if you want to change the world, start singing when you're up to your neck in mud.

    When Dee Dee Bridgewater learned that she would become a 2017 NEA Jazz Master, a series of thoughts and feelings flooded her mind. “It was so far out of my orbit and just my whole sphere of thinking,” she said in a conversation at NPR this spring, hours before she formally received her award.

    She's 66-far from retirement age in jazz, and on the extreme forward edge of the NEA Jazz Masters people. So she was aware of her relative youth in the field She also recognized that there haven't been many women in the ranks of NEA Jazz Masters: fewer than 20, out of 145. That idea led her to reflect on her predecessors (前任): legendary singers like Betty Carter* who was seated back in 1992, and Abbey Lincoln, who received the nod in 2003.

    Bridgewater sought inspiration and advice from both Carter and Lincoln, as she recalls in this period of Jazz Night, which features music recorded during the season opener for Jazz at Lincoln Center. On a program called “Songs of Freedom”, organized by drummer Ulysses Owens, Jr., Bridgewater sang material associated with Lincoln as well as Nina Simone: an extremely angry song of the civil rights movement, like “Mississippi Goddam”.

    A separate concert, “Songs We Love”, found Bridgewater singing less politically charged (but still exciting) fare like “St. James Infirmary”, which appears on her most recent album. In words as well as music, this period reveals how seriously Bridgewater takes that responsibility, seeing as how it connects to her own experience in the jazz lineage. But maybe “seriously” isn't the right word when it comes to Dee Dee, whose effervescence (欢腾) shines through even in a reflective mood. Join her here for a while; she's excellent company, no more or less so now that mastery is officially a part of her resume.

    Every man wants his son to be somewhat of a clone, not in features but in footsteps. As he grows you also age, and your ambitions become more unachievable. You begin to realize that your boy, in your footsteps, could probably accomplish what you hoped for. But footsteps can be muddied and they can go off in different directions.

    My son Jody has hated school since day one in kindergarten. Science projects waited until the last moment. Book reports weren't written until the final threat.

    I've been a newspaperman all my adult life. My daughter is a university graduate working towards her master's degree in English. But Jody? When he entered the tenth grade he became a “vo-tech” student (技校学生). They're called “motorheads” by the rest of the student body.

    When a secretary in my office first called him “motorhead”, I was shocked. “Hey, he's a good kid,” I wanted to say. “And smart, really.”

I learned later that motorheads are, indeed, different. They usually have dirty hands and wear dirty work clothes. And they don't often make school honor rolls (光荣榜).

    But being the parent of a motorhead is itself an experience in education. We who labor in clean shirts in offices don't have the abilities that motorheads have. I began to learn this when I had my car crashed. The cost to repair it was estimated at $800. “Hey, I can fix it,” said Jody. I doubted it, but let him go ahead, for I had nothing to lose.

    My son, with other motorheads, fixed the car. They got parts from a junkyard, and ability from vo-tech classes. The cost was $25 instead of $800.

Since that first repair job, a broken air-conditioner, a non-functioning washer and a non-toasting toaster have been fixed. Neighbours and co-workers trust their car repairs to him.

    These kids are happiest when doing repairs. They joke and laugh and are living in their own relaxed world. And their minds are bright despite their dirty hands and clothes.

    I have learned a lot from my motorhead: publishers need printers, engineers need mechanics, and architects need builders. Most important, I have learned that fathers don't need clones in footsteps or anywhere else.

My son may never make the school honor roll. But he made mine.