Nowadays it is common that people are buying more products and services than ever before through the Internet, so do Americans. And experts say the popularity of online sales is likely to spread to other countries. Online sales now represent as much as 10% of all retail sales in the United States. This has led traditional stores to seek new ways to keep their customers loyal.

Taking Lynne for example, she made good use of the Internet. She used the Internet to buy everything she needed for her Wedding and holiday gifts for her husband and daughter. Other than food, 90% of her purchases were made on her home computer. "I find that, by being able to go online, choose the things that I need, and have them delivered to me right at my doorstep, I eliminate all the driving, all the crowds, all the noise of that, and I usually get a better selection."

    There are a lot of people like her. Experts say American online shopping hit records in both November and December.57% of Americans have bought something electronically. Store owners worry that this growing amount of online sales will hurt their business. Cornell University marketing professor Ed Melaughlin says they can keep their customers by selling goods like clothing, which buyers may want to see and try on before purchasing. The stores could also offer things that are difficult to ship. Besides, some stores can please customers by offering to repair electronic products.

Bill Martin is the founder of Shopper Trak. His business helps stores learn about their customers. He said, "There is still a lot of emotion in the buying decision, you know, that takes place. Often you need that last sense of "Boy, this is exactly what I want before you are ready to part with money, and you can't always get that online. It's a rather cold process."

    While e-commerce worries some business owners, the only worry for delivery services is keeping up with the number of packages. UPS manager Dana Kline says her company is very busy at this time of the year.

    UPS is so busy that it has filled 55,000 temporary work positions during the holiday season.

    Most painters discover a style of painting that is fit for them and stick to that, especially if people admire their pictures. But Picasso, the great Spanish painter, was like a man who had not yet found his own particular style of painting. He kept on struggling to find the perfect expression till his death in 1973.

    Some of Picasso's paintings are rich, soft colored and beautiful. Others are ugly and cruel and strange. But such paintings allow us to imagine things for ourselves. They force us to say to ourselves, “What does he see that makes him paint like that?” And we begin to look under the surface of the things we see.

    Picasso painted thousands of pictures in different styles. Sometimes he painted the natural look of things. Sometimes he seemed to break them apart and throw the pieces in our faces. He showed us what the mind knows as well as what the eyes see. At the age of 90,he remained as curious about the world as he had been when he was young. That is why people have called him “the youngest painter in the world.”

    Recent summer temperatures in parts of Australia were high enough to melt asphalt. As global warming speeds up the heat and climatic events increase, many plants may be unable to cope. But at least one species of eucalyptus tree can resist extreme heat by continuing to “sweat” when other essential processes stop, a new study finds.

    As plants change sunlight into food, or photosynthesize (光合作用), they absorb carbon dioxide through pores on their leaves. These pores also release water via transpiration(蒸腾), which circulates nutrients through the plant and helps cool it by evaporation(蒸发). But exceptionally high temperatures are known to greatly reduce photosynthesis—and most existing plant models suggest this should also decrease transpiration, leaving trees in danger of fatally overheating. Because it is difficult for scientists to control and vary trees' conditions in their natural environment, little is known about how individual species handle this situation.

    Ecologist John Drake of the S.U.N.Y. College of Environmental Science and Forestry and his colleagues grew a dozen Parramatta red gum (Eucalyptus parramattensis) trees in large, climate-controlled plastic pods that separated the trees from the surrounding forest for a year in Richmond, Australia. Six of the trees were grown at surrounding air temperatures and six at temperatures three degrees Celsius higher. The researchers withheld (扣留) water from the surface soil of all 12 trees for a month to imitate a mild dry spell, then induced a four-day “extreme” heat wave: They raised the maximum temperatures in half of the pods（three with surrounding temperatures and three of the warmer ones）— to 44 degrees ℃.

    Photosynthesis ground to a near halt in the trees facing the artificial heat wave. But to the researchers' surprise, these trees continued to transpire at close-to-normal levels, effectively cooling themselves and their surroundings. The trees grown in warmer conditions coped just as well as the others, and photosynthesis rates bounced back to normal after the heat wave passed, Drake and his colleagues reported online in Global Change Biology.

    The researchers think the Parramatta red gums were able to effectively sweat — even without photosynthesis — because they are particularly good at tapping into water deep in the soil. But if a heat wave and a severe drought (干旱) were to hit at the same time and the groundwater was exhausted, the trees may not be so lucky, Drake says.

    Other scientists call the finding encouraging. “It's definitely good news,” says Trevor Keenan, an ecologist at Lawrence Berkeley National Laboratory, who was not part of the study. “It would be very interesting to know how this translates to other species,” he adds. Drake hopes to conduct similar experiments with trees common in North America.

    Artificial Intelligence (AI) is making it possible for companies to monitor workers' behavior in great detail and in real time. Start to slack off (懈怠), and AI could talk to your boss.

    One company offering such services is London-based start-up Status Today. Its AI platform relies on a regular supply of employee data, including everything from the files you access to when you use a key card. From this, it builds a picture of how employees normally function and signals any unusual performance. The idea is to spot when someone might become a security risk by doing something different from their usual behavioral patterns. “All of this gives us fingerprint of a user, so if we think the fingerprint doesn't match, we raise a warning”, says Mircea Dumitrescu, the company's chief technology officer.

    The system also aims to catch employee actions that could accidentally cause a security breach (漏洞), like opening malware (恶意软件).“We're not monitoring if your computer has a virus.” says Dumitrescu. “We're monitoring human behaviors.”

    But catching the security breach means monitoring everyone, and the AI can also be used to track employee productivity. “It seems like they are just using the reputation of AI to give an air of lawfulness to old-fashioned workplace surveillance (监视),” says Javier Ruiz Diaz of digital campaigning organization the Open Rights Group. “You have a right to privacy and you shouldn't be expected to give that up at work.”

    Exactly how companies use the system will be up to them, but it's hard to shake the picture of an AI constantly looking over employees' shoulders. “It will bother people, and that could be counterproductive if it affects their behavior,” says Paul Bemal at the University of East Anglia.

    Phil Legg at the University of the West of England says it will never catch every security risk. “If people know they're being monitored, they can change their behavior,” he says.

    The UK has a well­respected higher education system and some of the top universities and research instructions in the world. But to those who are new to it all, sometimes it can be confusing.

    October is usually the busiest month in the college calendar. Universities have something called Freshers' Week for their newcomers. It's a great opportunity to make new friends, join lots of clubs and settle into university life.

    However, having just left the comfort of home and all your friends behind，the prospect(前景) of meeting lots of strangers in big halls can be nerve­wracking (令人焦虑不安的). Where do you start? Who should you make friends with? Which clubs should you join?

    Luckily, there will be thousands of others in the same boat as you worrying about starting their university social life on the right foot. So just take it all in slowly. Don't rush into anything that you'll regret for the next three years.

    Here is some top advice from past students on how to survive Freshers' Week:

    Learn rules. Make sure you know British social etiquette(礼节). Have a few wine glasses and snacks handy for your housemates and friends.

    Be kind. Sometimes cups of tea or even slices of toast can give you a head start in making friends.

    Be sociable. The more active you are，the more likely you'll be to meet new people than if you're someone who never leaves his room.

    Bring a doorstop. Keep your door open when you're in and that sends positive messages to your neighbors that you're friendly.

    So with a bit of clever planning and effort, Freshers' Week can give you a great start to your university life and soon you'll be passing on your experience to next year's new recruits.

Concrete has served as the foundation stone of the construction industry for hundreds of years. However, the process of producing concrete is one of the most environmentally unfriendly processes in the world. In the process, not only is carbon dioxide（二氧化碳）released into the air by the energy used to heat the limestone, but the limestone itself also gives out a huge amount of the element. 

Luckily, a number of start-ups throughout the world are using creative thinking to make the construction industry a whole lot more friendly for the planet. 

A Canadian company called CarbonCure, has found a way to inject（注入）concrete with carbon dioxide itself. Not only does this trap the carbon dioxide into the concrete, keeping it from running away into the atmosphere, but it also creates a super strong material called calcium carbonate, which reduces the total amount of concrete that needs to be used. 

California-based Brimstone, is creating carbon-negative concrete by doing away with limestone entirely and instead using silicate rock, a material that does not release carbon dioxide when heated. Instead, the process produces magnesium（镁）, which absorbs carbon dioxide, as the basis for their concrete. 

Additionally, researchers at Australia's RMIT University have recently released a study showing that adding coffee grounds instead of sand to concrete could make it much stronger, reducing both the amount of sand used, as well as the amount of concrete that would need to be used in the final product. 

The biggest barrier at this point is convincing members of the industry that the new types of concrete are safe to be used, according to Stacy Smedley, director at a nonprofit focused on decarbonizing construction. 

Hopefully these new solutions to the environmental problems of concrete will soon be widely adopted. Given the significant part the construction industry has in releasing carbon dioxide into the atmosphere, great improvements can be made when more environmentally-friendly materials are used.