A new study finds that young females in one group of African chimps(黑猩猩) use sticks as dolls more than their male peers (同龄) do, often treating pieces of wood like a mother chimp caring for a baby. In human cultures around the world, girls play with dolls and pretend that the toys are babies far more than boys do.

    Chimp observations, collected over 14 years of field work with the Kanyawara chimp community in Kibale National Park in Ugandan, provide the first evidence of a nonhuman animal in the wild that exhibits sex differences in how it plays. This finding supports an argument that biology as well as society underlies boys' and girls' different toy preferences.

    Stick play occurred most commonly between ages 3 and 9. Females spent a lot more time carrying sticks than males did. Young male chimps occasionally used sticks to mimic(模仿) childcare. "Far more often, they fought with sticks, an infrequent behavior among females," say Sonya Kahlenberg of Bates College in Lewiston, Maine, and Richard Wrangham of Harvard University.

    "Biological differences between the sexes make female chimps more receptive to stick-mothering than males," says Wrangham.

    Consistent with reported cultural traditions among adult chimps, Kanyawara youngsters learned from each other to play with sticks as if caring for babies. Stick play among young chimps showed no evidence of being directly influenced by older chimps. Child-bearing females never played with sticks and thus didn't model such behavior for younger chimps.

    Young females carried sticks for anywhere from a few minutes to several hours. They often rested in nests with their sticks, sometimes playing with them much as chimp mothers play with their babies though they didn't get any form of teaching from the adults.

French surgeons have performed what they said on Wednesday was the world's first partial face transplant（移植）— giving a new nose, chin and lips to a woman attacked by a dog.

    Specialists from two French hospitals carried out the operation on a 38-year-old woman on Sunday in the northern city of Amiens by taking the face from a brain-dead woman, who had hanged herself just hours before the operation. Her family agreed on the operation.

    “The patient is in an excellent state and the transplant looks normal,” the hospitals said in a brief statement after waiting three days to announce the pioneering surgery.

    The woman had been left without a nose and lips after the dog attacked her last May, and was unable to talk or chew properly. Such injuries are “extremely difficult, if not impossible” to repair using normal surgical techniques, the statement said.

    The statement did not say what the woman would look like when she had fully recovered, but medical experts said she was unlikely to resemble the woman who had been the source of her new face.

    The operation was led by Jean-Michel Dubernard, a specialist from a hospital in Lyon who has also carried out hand transplants.

    Skin transplants have long been used to treat burns and other injuries, but operations around the mouth and nose have been considered very difficult because of the area's high sensitivity（敏感） to foreign tissue.

    Teams in France, the United States and Britain had been developing techniques to make face transplants a reality

    There was a short-term risk for the patient if blood vessels became blocked, a medium-term danger of her body rejecting the new skin and a long-term possibility that the drugs used could cause cancers.

    Experts say that although such medical advances should be celebrated, the transplant had thrown up moral（道德的）and ethical(伦理的)issues. Little is known about the psychological effect of three transplant.

    At any discussion of a job offer, money can be a deal breaker. Negotiating an attractive deal, however, can be hard for many job candidates because they lack the necessary skills or simply because they're too concerned that pushing for a high salary can cost them the job.

    These factors certainly can be hurdles (障碍), but it doesn't mean that you give up trying to get the best deal you can get. Needless to say, if money isn't a big factor in your decision, you still need to make sure that the deal you're accepting is fair compared to what's offered in the market. Selling yourself short once can impact your future salaries and set you back financially.

    Here are common mistakes that many jobseekers commit in negotiating money.

    Negotiate too early. Timing is of essence in any negotiation, and negotiating a salary too early in the process can cost you dearly. Many employers, in fact, rank this as one of the biggest mistakes job candidates make. The best timing to begin a salary discussion is after you and your future employer are nearly sure that you've been selected for the position.

    Abandon professionalism. It's common that people, after going through a long recruitment process, can be shocked that the salary offered is significantly below their expectations. If you find yourself in this situation, don't abandon your professional attitude or throw a fit. This likely will get you nowhere except the door.

    There're two options to this situation: the first is that the employer is inflexible (不灵活的) about the budget, and in this case, you may just leave and make a graceful exit from the hiring process.

    The second option is that there's some negotiation room for the hiring manager with other decision makers in the organization. If this is the case, you may be surprised that a final push with a positive attitude and a well-delivered presentation about your skills and market price can get you closer to your expected salary. Still, if this is not acceptable, you don't have to take it.

The least-visited countries in the world

    It's every traveler's dream — a corner of the planet still undisturbed by tourists. And obviously, such places do exist. The United Nations World Tourism Organization lately reported the four least-visited countries globally.

    Liechtenstein (69,000)

    The sixth smallest country in the world is also one of the most undiscovered.

    Lying between Austria and Switzerland, Liechtenstein is an outdoor enthusiast's playground. It's the only country in the world to be totally in the Alps and a summer destination for hiking and cycling and snow-covered skiing perfection in winter, for those who can afford it.

    French Guiana (199,000)

    French Guiana is the least-visited country in South America, with some of the world's most diverse plant and animal life.

    While there is much to attract tourists to the area, not least its miles of jungle, the construction is in need of some attention.

    Montserrat (9,000)

    Once a popular holiday spot, this Lesser Antilles island has never quite recovered from a series of natural disasters. Hurricane Hugo in 1989 hit 90 per cent of the island and in 1995 the Soufriere Hills volcano erupted.

    These days, its volcano is now actually one of Montserra's main attractions, together with its beautiful beaches. Visitors can also go diving in its clear waters.

    Comoros (24,000)

    This collection of islands in the Indian Ocean near Madagascar serves as the perfect destination for those who want to get away from everyday city life.

Comoros offers beautiful volcanic scenery, fruitful forests, and remote sleepy towns. There are even some of the best undiscovered reefs(礁) just waiting to be explored by divers.

    Starbucks will stop using plastic straws from its stores globally by 2020, in a nod to the growing push for businesses to be more environmentally friendly. The Seattle-based company said on Monday it will instead use straws made from other materials, and lids designed not to need straws. McDonald's also recently said it would switch to paper straws in the UK and Ireland by next year, and test alternatives to plastic straws in some US locations. In February, Dunkin' Donuts said that it would refuse polystyrene foam (塑料泡沫) cups from its stores by 2020.

    Environmental activists have been pressuring businesses to ditch plastic straws because they can end up in the ocean and hurt marine life. The push gained great support after a video in 2015 showed rescuers removing a straw from a sea turtle's nose in great detail. Local governments have also been looking at the issue. Last week, Seattle's ban on single-use plastic straws and utensils in food service outlets took effect, and Starbucks says it already offers alternative straws there. Similar proposals are being considered elsewhere, including New York and San Francisco.

    While straws have become a highly-concerned issue, they make up only about 4% of the plastic trash by number of pieces, and far less by weight. Straws add up to only about 2,000 tons of the nearly 9m tons of plastic waste that hits waters each year.

    Nezha is the subject of the latest feature, which officially opens in cinemas in China on Friday. Nezha has earned hot reviews and is ranked higher than Monkey King: Hero is Back. It is also China's first 3D animated feature film released in IMAX format.

    Since July 13, previews of the film have taken more than 140 million yuan at the box office and the film has a score of 8.8 points (out of 10) on China's largest filming rating site, Douban. It took Jokalate Yang Yu, the film's director and screenwriter, two years to improve the script (剧本) of Nezha, and the film was in production for three years. It is the most complex animated production ever made in China. Nezha has more than 1,300 special effects shots, and it took over 20 Chinese special-effects studios, employing more than 1,600 people, to realize the film's fairy tale setting, the mysterious Dragon King's palace and a fight between fire and water. One splendid scene alone took two months to complete.

    Yang made up his mind to produce an animated film on the theme of breaking the traditional styles and changing fate to the opposite. Yang chose Nezha as his vehicle, the representative of the rebellious (叛逆的) but righteous youth. However, compared with the original novel and past animated versions, the relationships between the characters are given modern meaning. In Yang's film he is fighting prejudice: Nezha is hated and feared. But Nezha believes his fate is not predetermined and that he can choose to be a devil (恶魔) or a god.

    "After watching so many domestic animated films, only Nezha and Monkey King: Hero is Back have made me fascinated," a Weibo user commented under the promotional video.

    "Epic! I finished watching Nezha in tears. The content-rich story, vivid characters, and amazing visual effects, work together to create a 110-minute roller-coaster (过山车) watching experience," a Douban user commented.

    "Bravo! Couldn't believe a domestic animated film can be created with such a well-developed story. The image of Nezha in this film has been overturned but his rebellious spirit is well-established. I'm sure Nezha is gonna go viral this summer!" reads another comment on Douban.