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.

    Have you ever been to London? Here is some hotel information for you.

    Kingsway Hall Hotel

    We offer quality service (优质服务) in Kingsway Hall Hotel. This location puts guests in easy reach of many places, such as the British Museum and Piccadilly Circus. Our hotel also has modern Western food, and offers a perfect dining environment. The lounge bar is a comfortable place to enjoy a drink while watching the tourists. There are hundreds of dining choices within walking distance. Non-smoking rooms are ready for guests.

    Hilton Docklands Riverside

    Located on the bank of the Thames, our hotel is about two miles east of Tower Bridge and 36 miles from London Heathrow Airport. Our hotel has a beauty salon, a flower shop and a swimming pool. The hotel also offers different kinds of service：laundry (洗衣店) services, babysitting, shining shoes, and local area transportation.

    Windermere Hotel

Located in the center of London, our hotel puts guests within easy reach of London's well-known buildings. Buckingham Palace and the Royal Parks are just a short walk away. Within 1.5 miles you can visit Westminster Abbey and the Houses of Parliament. The theatres, Harrods shopping centre, and the designer shops of Sloane Square and Knightsbridge are all only a short walk away or a taxi ride away.

    Life in the summertime is often full of pests. Like most Long Island homeowners, I want to ensure my suburban life with pest-free living. So it was with wide-eyed wonder that I greeted the smiling exterminator (灭虫者) who rang my bell.

    “We'll be serving your neighbors, Mike and Sarah (I'm not familiar with either one by name),” he waved in the other direction. “Since we'll have a team here tomorrow, we're offering a discount.” He came out with numbers beginning from $299 then in seconds to $89.

    “You've probably been seeing the ant hills around.” he moved toward my front walkway and lawn. “And have you seen the bees that dig nests in the ground?” he continued with his head shaking up and down pushing me to do the same.

    “What we do is spray three feet out from your foundation and three feet up.” As he was talking, and without breaking eye contact, he opened his iPad cover and began operating at the screen to show me frightening images. “It also kills other pests, like spiders. It is the best pesticide (杀虫剂),” he said, pausing for effect.

    He then went into soft talk to close the deal, correctly foreseeing that I would be concerned about safety and the environmental impact on my vegetable garden, plants and our little patch of planet here on Long Island. “The products are environmentally responsible, safe with children and pets,” he said.

    I'm unkind when it comes to unwanted visitors entering on my out-of-doors moments. Any insect found in my house or on my deck is bound to be poisoned or pancaked.

    Unfortunately for the exterminator, just as I was considering making an appointment, Billy, my fearless husband, pulled into our driveway, which made me ask for a business card out of politeness instead.

    Children exposed to "safe" levels of air pollution in the womb(子宫) develop brain damage that damages their concentration, a study has shown.

    The research is the first too link common pollutants such as nitrogen(氮) dioxide and soot(油烟) to changes in the brains of unborn babies that mean they may struggle to focus at school in later life. The findings suggest that even comparatively clean city air could lead to worse academic performance and an increased risk of mental health problems such as addition or attention deficit hyperactivity disorder(缺陷多动障碍).

    In recent years scientists have found that children who grow up surrounded by air pollution are more likely to have a broad range of "neuro(神经)­developmental" difficulties, including autism and various kinds of cognitive(认知) damage. However, only a handful of studies have looked at the ways in which the poisonous gases and microscopic particles(微粒) that mothers and young children take in affect the brain during critical stages of its growth.

    A group led by Monica Guxens, of the Barcelona Institute for Global Health, found that exposure to air pollution before birth appeared to have slowed the development of several brain regions that play an important role in people's capacity for self­denial and sustained effort. This lack of inhibition could in turn cause "cognitive delays" when the children get older, the scientists argue in Biological Psychiatry.

    "We need this function in our daily life," Dr. Guxens said. "It controls our impulses(冲动) and our selective attention. Children need it to learn and for making decisions in later life. We're interested to see what will happen: is there going to be an impact on their academic work, are there going to be clinical implications? It might be that this will lead to problems later."

    The results were drawn from MRI scans of 873 children between the ages of six and ten in Rotterdam. Even though 99.5 percent of their mothers had lived with nanoparticle pollution levels well below EU legal limits while they were pregnant the pollution still appeared to have taken its toll(伤亡人数).

    Children who had been exposed to more pollution in the womb did worse on a test of their ability to block out irrelevant stimuli(刺激). They also had thinner outer layers in the precuneus(楔前叶) and the rostral middle frontal regions of their brains, both of which are involved in cognitive inhibition, which refers to the mind's ability to tune out stimuli that are irrelevant to the task at hand or to the mind's current state.

    Experiments on animals show that so­called fine particles are able to pass through the placenta and affect the brain of the fetus(胎儿). Dr Guxens said there were probably no such thing as a safe concentration of air pollution.

A team in Europe are working with wood, but not in the usual ways. They are not carpenters（木匠）. Instead, they are scientists exploring how wood can lead to a greener electronic device, a transistor（晶体管）made from balsa wood, whose production releases less climate-warming gas into the air.

Transistors play an important role in computers and other devices. They act like tiny switches to control the flow of electricity. Engineers use them to process and store data. Today's laptops may host billions of them. So they must be tiny—only a little wider than a strand of DNA.

The new transistor being built by physicist Isak Engquist and his team at Sweden's Linköping University isn't as small as those. Big enough to see and hold, it can stand only an electric pressure that pushes electrons along. And it controls a current using charged particles（粒子）called ions.

This new technology shows a "proof of concept" that the idea can work, even if the new device is not yet ready to put into today's electronics. "While it seems large by today's standards, such a transistor still might prove useful for electronics that require low electric pressures," says Engquist.

"The new transistor suggests that future electronic devices might be made in living plants," Daniel Simon, a physicist in the team, says. "Imagine peeling away some bar k from a living tree," he says, "and stamping electronic circuits into the living wood."

In fact, Engquist says, "There are so many ways we can use wood and the components of wood that we would never have thought of." For instance, he can now imagine a wood-based sensor that could monitor crop health, measure pollution or survey a forest for fire risk.

Traditional Chinese festivals always have {#blank#}1{#/blank#} (they)symbolic foods. The Dragon Boat Festival-or Duanwu Festival-features zongzi, or sticky rice dumplings. For the Dragon Boat Festival, which {#blank#}2{#/blank#} (fall)on the fifth day of the fifth month of the lunar calendar, the core ideas are getting rid of diseases, avoiding disasters and {#blank#}3{#/blank#} (wish)for good health. 

Wen Yiduo, {#blank#}4{#/blank#} poet and academic, wrote that on the fifth day of the fifth month, people threw rice dumplings into the water and raced the dragon boats activities to express their fear of the dragon below and the hope that it will not make trouble in the {#blank#}5{#/blank#} (day)to come. 

The most {#blank#}6{#/blank#} (wide)known story of Duanwu Festival is that it was started {#blank#}7{#/blank#} (remember) Qu Yuan, {#blank#}8{#/blank#} committed suicide on the fifth day of the fifth lunar month. People threw sticky rice dumplings into the river {#blank#}9{#/blank#} the dragon underwater would not eat his body. 

Eating rice dumplings {#blank#}10{#/blank#} (be)one shared custom. There are also traditions unique to other ethnicities. For Dai people in Yunnan, for example, Duanwu Festival is an annual opportunity to express admiration to others.