A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    Few laws are so effective that you can see results just days after they take effect. But in the nine days since the federal cigarette tax more than doubled-to $1.01 per pack-smokers have jammed telephone "quit lines" across the country seeking to kick the habit.

    This is not a surprise to public health advocates. They've studied the effect of state tax increases for years, finding that smokers, especially teens, are price sensitive. Nor is it a shock to the industry, which fiercely fights every tax increase.

    The only wonder is that so many states insist on closing their ears to the message. Tobacco taxes improve public health, they raise money and most particularly, they deter people from taking up the habit as teens, which is when nearly all smokers are addicted. Yet the rate of taxation varies widely.

    In Manhattan, for instance, which has the highest tax in the nation, a pack of Marlboro Light Kings cost $10.06 at one drugstore Wednesday. In Charleston, S.C., where the 7-cent-a-pack tax is the lowest in the nation, the price was $4.78.

    The influence is obvious.

    In New York, high school smoking hit a new low in the latest surveys-13.8%, far below the national average. By comparison, 26% of high school students smoke in Kentucky. Other low-tax states have similarly depressing teen-smoking records.

    Hal Rogers, Representative from Kentucky, like those who are against high tobacco taxes, argues that the burden of the tax falls on low-income Americans "who choose to smoke".

    That's true. But there is more reason in keeping future generations of low-income workers from getting hooked in the first place. As for today's adults, if the new tax drives them to quit, they will have more to spend on their families, cut their risk of cancer and heart disease and feel better.

    No one knows for sure when advertising first started. It is possible that it grew out of the discovery that some people did certain kinds of work better than others did them. That led to the concept of specialization, which means that people would specialize, or focus, on doing one specific job.

    Let's take a man we'll call Mr. Fielder, for example. He did everything connected with farming. He planted seeds, tended the fields, and harvested and sold his crops. At the same time, he did many other jobs on the farm. However, he didn't make the bricks for his house, grind the wheat for his flour, or cut his trees into boards. He also did not make the plows(犁), the work boots, or any of the other hundreds of things a farm needs. Instead, he got them from people who specialized in doing each of those things.

    Suppose there was another man we shall call Mr. Plowright. Using what he knew about farming and working with iron, Mr. Plowright invented a plow that made farming easier. Mr. Plowright did not really like farming himself and wanted to specialize in making really good  plows. Perhaps, he thought, other farmers will trade what they grow for one of my plows.

    How did Mr. Plowright let people know what he was doing? Why, he advertised, of course. First he opened a shop and then he put up a sign outside the shop to attract customers. That sign may have been no more than a plow carved into a piece of wood and a simple arrow pointing to the shop door. It was probably all the information people needed to find Mr. Plowright and his really good plows.

    Many historians believe that the first outdoor signs were used about five thousand years ago. Even before most people could read, they understood such signs. Shopkeepers would carve into stone, clay, or wood symbols for the products they had for sale.

    A medium, in advertising talk, is the way you communicate your message. You might say that the first medium used in advertising was signs with symbols. The second medium was audio, or sound, although that term is not used exactly in the way we use it today. Originally, just the human voice and maybe some kind of simple instrument, such as a bell, were used to get people's attention.

    A crier, in the historical sense, is not someone who weeps easily. It is someone, probably a man, with a voice loud enough to be heard over the other noises of a city. In ancient Egypt, shopkeepers might hire such a person to spread the news about their products. Often this primitive form of advertising involved a newly arrived ship loaded with goods. Perhaps the crier described the goods, explained where they came from, and praised their quality. His job was, in other words, not too different from a TV or radio commercial in today's world.

    You often can choose a private setting when you browse(浏览) the internet. But be forewarned: It may not afford nearly as much privacy as you expect. That's the finding of a new study.

    Major web browsers, such as Google's Chrome and Apple's Safari, often a private-browsing option. It's sometimes referred to as “incognito.” This option lets you surf the Internet browser and saves a record into its history of each page that you visited. And what sites you visit won't affect the suggestions your browser makes the next time you're filling out an online form.

Many people believe—incorrectly— that the incognito setting protects them more broadly. Most believe it even after reading a web browser's explanation of the incognito mode.

    For instance, a new study had 460 people read web browsers' descriptions of private browsing. Each person read one of 13 descriptions. Then the participants answered questions about how private they thought their browsing would be while using this tool. The volunteers didn't understand the incognito mode. This was true no matter which browser explanation they had read. The researchers reported their findings on April 26 at the 2018 World Wide Web Conference in Lyon, France.

    More than half of the volunteers thought that if they logged into a Google account through a private window, Google wouldn't keep a record of their search history. Not true. And about one in every four participants thought private browsing hid their device's IP address. That's wrong, too.

    Blase Ur was one of the study's authors. He's an expert in computer security and privacy in Illinois at the University of Chicago. Companies could clear up this confusion by giving better explanations of the incognito mode, his team says. For example, the browsers should avoid vague（模糊).The web browser Opera, for instance, promises users that “your secrets are safe.” Nope Firefox encourages users to “browse like no one's watching.” In fact, someone might be. (If you'd like to know more about the research information, please click here.)

The Art of Chinese Xinjiang Uyghur Muqam is a {#blank#}1{#/blank#}( represent ) name of various kinds of Muqam in Northwest China' s Xinjiang Uyghur Autonomous Region,{#blank#}2{#/blank#}was declared one of the UNESCO Masterpieces of the Oral and Intangible Heritage of Humanity in 2005. 

Muqam ,{#blank#}3{#/blank#}( recognise ) as the mother of Uyghur music , is not only{#blank#}4{#/blank#}artistic creation with a long history, but also a record of {#blank#}5{#/blank#}( communicate ) between China and the regions to the west of it in history . It can be found in 19 countries and regions in Central , South , and West Asia , and North Africa , which is {#blank#}6{#/blank#}( particular ) due to Xinjiang' s central location along the Silk Road. 

In Muqam ensembles（乐团）, the lead instruments, called satar, are made from local materials and vary in form. The dancing skills involve unique steps, rhythms, and formations as well as{#blank#}7{#/blank#}( figure ) such as flower-picking-by-mouth, bowl-carrying-on-head, and imitation of animals in solo dances. 

Since the 1950s, every possible means{#blank#}8{#/blank#}( use ) to preserve the Twelve Muqam by the Chinese government. About 20 study centres have been set up {#blank#}9{#/blank#}( train ) professional researchers on Muqam. Moreover, the government has introduced Muqam {#blank#}10{#/blank#}the national artistic education system.

This summer has brought ex treme heat and droughts to places around the world. The droughts are leading to serious problems and the effects of the droughts are likely to be felt for years. Droughts aren't new, but Earth's rising temperatures because of global warming are making them much harder to avoid. The drought in the Horn of Africa may be the most serious situation. For several years, the area has had very little rain during the rainy seasons. The dry conditions have killed millions of farm animals and destroyed the crops of farmers.

The drought is causing energy problems in Europe, too. The low water levels have cut the amount of hydroelectric power that can be produced. Some rivers are so low that the heavy boats that carry coal can't travel on them.

Farmers in California and Arizona have been hit particularly hard. California has put limits on water use across the state. Now water is being limited in other places. When there are water limits, farmers aren't able to grow as many crops. That can drive up food prices, and that affects everyone.

China is facing similar problems. The drought has dried up much of the water in the Yangtze River. That has cut the amount of energy produced by the world's largest da m by 40%. China hasn't been able to produce enough energy, since millions of people are using electricity to keep cool. The government is calling on the public to turn off the air conditioner when it is not too hot. The country is trying to make it rain by shooting chemicals into clouds. But this is an uncertain and temporary response.

There are no easy solutions to any of these droughts. It took years to create the climate crisis, and it will take a long time to get it under control. For now, governments and people will need to care fully manage water supplies and other resources to limit the damage as much as possible.