【推荐2】Peter loved to shop used articles. Almost a month ago, he bought a popular word game that used little pieces of wood with different letters on them. As he was purchasing it, the salesgirl said, “Oh, look, the game box hasn’t even been opened yet. That might be worth some money.”

Peter examined the box and, sure enough, it was completely covered in factory-sealed plastic. And he saw a date of 1973 on the back of the box.

“You should put that up for auction (拍卖) on the Internet, and see what happens,” the salesgirl said.

“Yes, you’re right. People like something rare,” Peter agreed. “I can’t imagine there being very many unopened boxes of this game still around 40 years later.”

“Don’t forget to tell me if you sell it,” the salesgirl smiled.

“No problem,” Peter said.

After he got home, Peter went online to several auction websites looking for his game. But he couldn’t find it. Then he typed in the name of the word game and hit Search. The search result was 543 websites containing information about the changes of the game. Over the years, the game had been produced using letters in different sizes and game boards in different colors. He also found some lists of game fans looking for various versions of the game. Peter emailed some of them, telling them what he had.

Two weeks later, Peter went back to the shop.

“Hello. Do you still remember the unopened word game?”

The salesgirl looked at him for a second, then recognized him and said, “Oh, hi!”

“I’ve got something for you,” Peter said. “I sold the game and made $1,000. Thank you for your suggestion.” He handed her three $100 bills.

“Wow!” the salesgirl cried out. “Thank you. I never expected it.”

【推荐3】America is a mobile society. Friendships between Americans can be close and real, yet disappear soon if situations change. Neither side feels hurt by this. Both may exchange Christmas greetings for a year or two, perhaps a few letters for a while—then no more. If the same two people meet again by chance, even years later, they pick up the friendship. This can be quite difficult for us Chinese to understand, because friendships between us flow more slowly but then may become lifelong feelings, extending (延伸) sometimes deeply into both families.

Americans are ready to receive us foreigners at their homes, share their holidays, and their home life. They will enjoy welcoming us and be pleased if we accept their hospitality (好客) easily, but truly can’t manage the time to do a great deal with a visitor outside their daily routine. They will probably expect us to get ourselves from the airport to our own hotel by bus. And they expect that we will phone them from there. Once we arrive at their homes, the welcome will be full, warm and real. We will find ourselves treated hospitably.

Another difficult point for us Chinese to understand Americans is that although they include us warmly in their personal everyday lives, they don’t show their politeness to us if it requires a great deal of time. This is usually the opposite of the practice in our country where we may be generous with our time. Sometimes, we, as hosts, will appear at airports even in the middle of the night to meet a friend. We may take days off to act as guides to our foreign friends. The Americans, however, express their welcome usually at homes. 

For the Americans, it is often considered more friendly to invite a friend to their homes than to go to restaurants, except for pure business matters. So accept their hospitality at home!

【推荐1】With almost all big employers in the United States now using artificial intelligence (AI) and automation in their hiring processes, the public is considering some urgent questions: How can you prevent discrimination in hiring when a machine is keeping the discrimination? What kind of methods might help?

Some 83% of employers, including 99% of Fortune 500 companies, now use some form of automated tools as part of their hiring process, said the Equal Employment Opportunity Commission’s ( EEOC) chair Charlotte Burrows, at a hearing on Tuesday. She said everyone needs to speak up on the debate over these technologies. “The risks are simply too high to leave this topic just to the experts.”

Last year, the EEOC issued some guidance around the use of cutting-edge hiring tools, noting many of their shortcomings. The agency found that resume( 简历) scanners which prioritize keywords and programs which evaluate a candidate’s facial expressions and speech patterns in video interviews can create discrimination. Take, for example, a video interview that analyses an applicant’s speech patterns to determine their ability to solve problems. A person with a speech problem might score low and automatically be screened out. The problem will be for the EEOC to root out discrimination or stop it from taking place.

The EEOC is considering the most appropriate ways to handle the problem. It’s agreed that inspections are necessary to ensure that the software used by companies avoids intentional or unintentional discrimination. But who would conduct those inspections is a more challenging question. Each option presents risks, Burrows pointed out. A third party may turn a blind eye to its clients, while a government-led inspection could potentially stop innovation.

In previous remarks, Burrows has noted the great potential that AI decision making tools have to improve the lives of Americans, but only when used properly. “We must work to ensure that these new technologies do not become a high-tech pathway to discrimination,” she said.

【推荐2】Of the more than 3,000 species of mosquitoes in the world, just a small number specialize in sucking human blood. How mosquitoes track us down so effectively isn’t currently known, but it matters, since they carry dangerous diseases which may cause death.

“In fact, stopping these annoying insects in their tracks could save up to half a million lives lost to those diseases each year,” said Carolyn Gauff, a professor of ecology and evolutionary biology at the Princeton Neuroscience Institute. That’s why Gauff’s team wanted to understand how they find and target humans.

Mosquitoes mostly choose what to bite based on odor (气味). Knowing how a potentially disease-carrying mosquito finds a person, while ignoring other warm-blooded animals, is a key question. But it’s not easy to answer, since any animal smell is made up of hundreds of chemicals mixed together in specific percentage. “The actual chemicals that are found in human odor are basically the same as the chemicals found in animal odor—it’s the percentages and the relative large amount of those substances in human mixtures that’s unique,” said Gauff.

To investigate, researchers decided to record neural activity in the brain of mosquitoes while exposing them to natural human and animal odor samples. They collected odor samples from about 40 different animals. When they compared some of those with the 16 human samples, something jumped out. Decanal is particularly rich in human skin. Common in the natural world, in humans, decanal comes from another, more complex substance. When one component of our skin’s natural oils, sapienic acid, breaks down, decanal is left over. This acid is only found in human beings. It’s what likely leads to the high levels of decanal that help the mosquitoes smell their way to us.

Understanding what the mosquitoes are targeting is only part of the story; knowing how they do it is also important. To see exactly how mosquitoes use this sense, scientists used genetically modified (转基因的) mosquitoes so that they could cut open mosquitoes’ heads and watch neurons firing when they’re exposed to human and animal odors. The research team already knew that mosquitoes have about 60 different types of neurons that sense odors, so when they looked in the insects’ brains, they thought they might see a lot of activities. But it was surprisingly quiet, meaning that the signal was perhaps quite simple, down to just a couple types of neurons. “One type of neuron responded really strongly to both humans and animals. Another type of neuron responded to both—but it responded much more strongly to humans than animals,” Gauff said.

How to keep mosquitoes’ decanal signal from being transmitted will be the research team’s next focus. Gauff hoped their current work could be used to make mosquito killers and attractants to prevent disease.

【推荐3】In the far north, well above the Arctic Circle in Alaska, ground squirrels(地松鼠) are like little balls within a deep hole in the ground. If you look at one, you might think it is dead. The squirrel is as cold as ice. Its body temperature is -2℃. Its heart beats only once every 15 seconds. Its breathing stops for minutes at a time.

It’s not exanimate, of course—just hibernating(冬眠). But spring is on its way to Alaska. As the days are becoming longer and the ground becomes warm, the Arctic ground squirrels will be warm, too. At first, the increase will be almost too small to notice. “You see them begin to breathe a little more quickly —see their heart rate speed up,” says Brian Barnes, a zoologist of the University of Alaska. “As they get up to 10℃ to 20℃, you see them shivering(颤抖) quite clearly,” he notes, “just as we shiver.” This shivering is a type of way to create heat. “Once their body temperatures rise above 30℃,” he says, “they wake up, clean themselves, and move.” A squirrel that looked dead a few hours before is now very much alive.

Arctic ground squirrels are among the world’s coolest hibernators. Chilling out(放松) for months at a time lets them grow in this extremely cold place, where food is short. By studying how ground squirrels hibernate, scientists hope to answer some big questions. Among them: How do these animals go from warm to cold and back again? And might people ever do the same? The ability to chill out could help humans who suffer from brain injuries and heart problems survive.