Sound travels very well through water-much better, in fact, than it does through air. So it shouldn't be surprising that many ocean animals make noise. They use sound to communicate and hunt. As biologist Brandon Southall says, “Their whole world is related to sound.”

    Dolphins whistle, organizing hunts. Lovesick whales sing so loudly they can be heard hundreds of miles away. But these days they aren't the only ones sounding off. They have more and more competition from human machines.

    Every day, thousands of huge container ships sail across the world's oceans. On top of the engine noise, the ships' propeller (螺旋桨) make a loud noise all the time. All that can make it hard for ocean animals trying to listen out for friends, or dinner. Animals swimming nearby a ship can be deafened or even killed.

    Underwater construction can also be dangerously loud. When construction machines called pile drivers were used during repairs to the San Francisco-Oakland Bay Bridge, dead fish appeared.

    Geologist (地质学家) pound on the seafloor too, trying to find oil wells and map Earth's surface. The results are useful lo science, but all that hammering probably gives ocean animal a headache.

    As people realize how important sound is to ocean animals, they are looking for ways to reduce human noise. Ships could get quieter just by slowing down. Engineers are also trying to find quieter propeller ships.

    Now some companies are using a simple invention called a bubble curtain, which makes sound waves passing through it lose energy and gel quieter. It seems to work - when bubble curtains were fixed on the San Francisco bridge project fish deaths dropped.

    We still have a lot to learn about sound in the oceans, but together we can help keep the sea a quieter place.

    Researchers found that walking around with a forced smile and fake happiness simply leads to people feeling unhappier. So, putting a brave face on your sadness could be harmful. The research also found that women suffered more than men when pretending to be happy.

    Dr. Brent Scott, who led the study, said employers should take note because forcing workers to smile when dealing with the public can result in bad outcomes. He said, “Smiling for the sake of smiling can lead to emotional tiredness, and that's bad for the organization.” He also said the research showed customer-service workers who had “fake smiles” throughout the day didn't want to work, so their productivity dropped.

    The study is one of the first of its kind to examine emotional expressions over a period of time and compare the different effects on men and women. Dr. Scott's team examined the effects of “surface acting”, or fake smiling, compared to “deep acting”, or making people smile by thinking of pleasant memories.

    Dr. Scott said, “Women were harmed more by surface acting, meaning their moods worsened even more than men's. However, they were helped more by deep acting, which means their moods improved more by thinking of pleasant memories.”

    According to Dr. Scott women tend to suffer more when pretending to be happy because they are expected to be more emotionally expressive than men. Therefore, forcing a smile while feeling down is more likely to go against their normal behavior and cause more harmful feelings.

    Although deep acting can improve moods a little in the short term, Dr. Scott says it's not a long-term solution to feeling unhappy. There have been some suggestions that if you do this over a long period you start to feel unreal. You're trying to develop positive emotions, but at the end of the day you may not feel like yourself any more.

    Monkeys seem to have a way with numbers.

    A team of researchers trained three Rhesus monkeys to associate 26 clearly different symbols consisting of numbers and selective letters with 0-25 drops of water or juice as a reward. The researchers then tested how the monkeys combined—or added—the symbols to get the reward.

    Here's how Harvard Medical School scientist Margaret Livingstone, who led the team, described the experiment: In their cages the monkeys were provided with touch screens. On one part of the screen, a symbol would appear, and on the other side two symbols inside a circle were shown. For example, the number 7 would flash on one side of the screen and the other end would have 9 and 8. If the monkeys touched the left side of the screen they would be rewarded with seven drops of water or juice; if they went for the circle, they would be rewarded with the sum of the numbers—17 in this example.

    After running hundreds of tests, the researchers noted that the monkeys would go for the higher values more than half the time, indicating that they were performing a calculation, not just memorizing the value of each combination.

    When the team examined the results of the experiment more closely, they noticed that the monkeys tended to underestimate（低估）a sum compared with a single symbol when the two were close in value—sometimes choosing, for example, a 13 over the sum of 8 and 6. The underestimation was systematic: When adding two numbers, the monkeys always paid attention to the larger of the two, and then added only a fraction（小部分）of the smaller number to it.

    "This indicates that there is a certain way quantity is represented in their brains, "Dr. Livingstone says. "But in this experiment what they're doing is paying more attention to the big number than the little one.”

Clair Hughes initiated her quest for frugal methodologies to extricate herself from a £3,500 educational advance that had spiraled into a financial overhang. This economic strategist commenced an online odyssey in search of vouchers that would provide her with markdowns on her purchases. She divulged that the full value of an item seldom left her wallet, proclaiming, "Deductions are perpetually accessible; the key lies in meticulous organization. Initially, I anticipated an onerous endeavor, but I have now assimilated this lifestyle to the point where it has become second nature. I have effortlessly amassed savings exceeding £15,000."

In the year 2010, Ms. Hughes directed her attention towards fiscal conservation when she relocated to share a domicile with her significant other, Shane Byrne, an instructor within the telecommunications sector. Seeking counsel through digital means, she implemented a series of astute financial maneuvers, such as transferring her financial overdraft to an account that levied no interest. Subsequently, after a few years, she encountered an online collective of individuals devoted to the art of voucher accumulation and resolved to experiment with their practices.

She dedicated considerable time to navigating the digital expanse in pursuit of vouchers, meticulously printing each one to accompany her on her commercial forays. Over the passage of time, she has secured some remarkable bargains. On one occasion, a pair of luminaries valued at £140 were hers for the mere sum of £35.

Two years prior, Ms. Hughes expanded her repertoire of economic strategies by incorporating rebate applications that offer monetary restitution on a spectrum of items from alcoholic beverages to personal care products. Post each commercial venture, she uploads visual documentation of her financial transactions, which are subsequently scrutinized, and restitution is granted on certain acquisitions.

Among her other premier recommendations for financial prudence, Ms. Hughes advocates participation in remunerative online surveys, which have yielded her a substantial cache of vouchers. She remarked, "I have encountered accounts of individuals gathering forsaken receipts from shopping carts to seek overlooked discounts. The extent to which vouchers and rebate applications have been of service to me is astonishing. The community significantly enhances my financial endeavors. There is invariably an individual prepared to elucidate the operational intricacies."

A 50- minute drive northwest of downtown Beijing, pops up a village, {#blank#}1{#/blank#} houses a shadow puppetry troupe(皮影戏剧团) and a theater, Beijing Long Zaitian Shadow Puppetry Theater. 

Shadow puppetry {#blank#}2{#/blank#}( see) as the prequel(前篇) to film and animation in China. In2011, the art landed a spot on the UNESCO Intangible Cultural Heritage List. 

Besides performances {#blank#}3{#/blank#}( create) by light and shadow, performers must master multiple skills as the plays combine painting, carving, opera {#blank#}4{#/blank#} literature. However, due to low income and a small market, few young people are willing {#blank#}5{#/blank#} ( learn) shadow puppetry. 

This particular troupe, however, stands out from the crowd: Average performer age is only 25. Moreover, of the 300 performers it has trained over the years, many are under 1. 4m in {#blank#}6{#/blank#} ( high). 

In 2006, Wang Xi, inheritor of Beijing Western- School Shadow Puppetry, {#blank#}7{#/blank#}( establish) the troup e in Beijing, and {#blank#}8{#/blank#} first four very short persons joined her two years later. After a four- month training, they picked up basic performance skills and started working in the theater. 

In 2021, the team designed Winter Olympics- themed shadow puppets. The puppets were gifted to foreign athletes during the Games. The troup e also staged {#blank#}9{#/blank#}( variety) plays introducing ice and snow sports through fairy tales. 

" We are lucky to have these people. They have been devoted {#blank#}10{#/blank#} the inheritance of shadow puppetry for over a decade, " Wang Xi said.