For families on vacation, a playground provides a welcome break. It can also provide a glimpse into the local culture，from the setup of the park to the ways families interact．Here are the designs that live up to that challenge．

Fruit and Scent Playground, Stockholm

    Is there a picky eater on a steady diet of chicken fingers and cheese? Perhaps a trip to Sweden's Fruit and Scent Playground will change his or her culinary(烹饪的)tune. This playground features a banana slide，an orange seesaw，pear huts，a watermelon jungle gym and a pair of cherry swings，all designed by public artist Johan Ferner Strom. Now, who can say you can't play with your food?

Nishi Rokugo Park, Tokyo

    Located between central Tokyo and the city of Kawasaki, Nishi Rokugo combines recycled rubber tires(橡胶轮胎)with traditional playground equipment. In total, more than 3,000 tires of different sizes are used to create tunnels, bridges, tall sculptures for climbing and, of course, tire swings. There's little shade, so you can visit here in the early morning or late afternoon for the most comfortable weather, and be sure to wear your play clothes.

    Bicentennial Children's Park, Santiago, Chile

    Bicentennial Children's playground in Metropolitan Park was built to celebrate 200 years of Chilean independence and improve the lives of Santiago citizens. Dozens of slides are built into the slope, creating a design completely complementary(互为补充的)of the surrounding landscape. Fountains offer some relief from the sun, and ample seating gives parents a place to relax.

    Adults understand what it feels like to be flooded with objects. Why do we often assume that more is more when it comes to kids and their belongings? The good news is that I can help my own kids learn earlier than I did how to live more with less.

    I found the pre-holidays a good time to encourage young children to donate less-used things, and it worked. Because of our efforts, our daughter Georgia did decide to donate a large bag of toys to a little girl whose mother was unable to pay for her holiday due to illness. She chose to sell a few larger objects that were less often used when we promised to put the money into her school fund(基金）(our kindergarten daughter is serious about becoming a doctor)

    For weeks, I've been thinking of bigger, deeper questions: How do we make it a habit for them? And how do we train ourselves to help them live with, need, and use less? Yesterday, I sat with my son, Shepherd, determined to test my own theory on this. I decided to play with him with only one toy for as long as it would keep his interest. I expected that one toy would keep his attention for about five minutes, ten minutes, max. I chose a red rubber ball-simple, universally available. We passed it, he tried to put it in his mouth, he tried bouncing it, rolling it, sitting on it, throwing it. It was totally, completely enough for him. Before I knew it an hour had passed and it was time to move on to lunch.

    We both became absorbed in the simplicity of playing together. He had my full attention and I had his. My little experiment to find joy in a single object worked for both of us.

    The World Bank is warning that the West Africa Ebola outbreak could seriously harm the economies (经济)of Guinea, Liberia and Sierra Leone unless action is taken quickly. World Bank President Jim Yong Kim spoke to reporters recently to discuss the effects of the Ebola spread.

    "Our findings show that if the virus(病毒)continues to spread, the economic cost to these countries could grow eight times by 2015. This would be a big catastrophe to their already weak economies," said Kim.

    Mr. Kim says, "saving lives and preventing new spread" is most important. The bank has given $117-million for an "immediate help." The World Bank President says the SARS outbreak between 2002 and 2004 showed how a disease could damage economies. 800 people died from SARS and the economic losses were up to $40-billion.

    Mr. Kim says SARS and the H1N1 outbreak of 2009 taught that fear and avoidance resulted in about 90-percent of the economic losses. That means the disease is causing two levels of economic damage.

    "There are two kinds of contagion(传染). One is connected with the virus itself and the second is connected with the spread of fear about the virus," said Kim.

    The World Bank thinks the losses to the economies of Liberia, Sierra Leone and Guinea will be big .Mr. Kim says losses could be about $97-million at the moment.

    Mr. Kim says fast action is necessary. He says getting the disease under control is still far away. That is because there are not enough health care workers in the affected areas. The World Bank President says the most important measure is to act quickly in order to limit economic losses.

    Emmoni Lopez used to take dance lessons while her older brothers wrestled – but it turned out that she liked wrestling better.

    Her mom wasn't surprised when Lopez told her she liked wrestling more than dance, and three years after Lopez took up the sport, she enjoys watching her daughter wrestle. Still, when a coach first asked Lopez to join his program, her mom hesitated– she never thought her daughter would want to be a wrestler.

    Lopez is among a growing number of girls who are taking up wrestling. Officials with youth organizations in Chicago and the Illinois Kids Wrestling Federation (IKWF) said they've seen the number of girls participating in the sport take off in recent years.

In Lopez's program, about half of the students participating in the organization's free youth wrestling camp this summer are girls, coach Frankie Zepeda said.

    Many of the girls Zepeda sees become interested in wrestling through their brothers, he said.

    “They probably just learn to … fight back,” he said.

    One of those was Yamilet Aguirre. She took up wrestling because she was bored just watching her brother wrestle, she said.

    “I can have fun doing it,” she said. “And I can prove girls are just as strong as boys are.”

    Though girls have competed on high school wrestling teams in Illinois for years, coaches and female wrestlers said there weren't many participating a decade ago.

    “It's really picked up over the last few years,” said Jim Considine, president of the IKWF.

    Between the 2015-16 and 2017-18 seasons, the number of girls registered with IKWF grew from 363 to 503, and more of the organization's events are featuring a girls-only division. Girls and boys wrestle together during the season through IKWF, but there's a girls-only championship at the end of the year.

    And by adding female wrestling programs, colleges are giving girls and young women another option.

    “Female wrestling isn't something unacceptable anymore,” Considine said. “Things have happened so quickly. Ten years ago, you'd never have dreamed of doing this.”

    Loud cheers and applause broke out at NASA's Jet Propulsion Lab on Monday, November 25, 2018, as the unmanned lander, called Insight, touched down on Mars, after nearly seven years from design to launch to landing.

    The great arrival of the spacecraft­designed to listen for quakes and shakes as a way to discover the Red Planet's inner secrets, how it formed billions of years ago and, how other planets like Earth took shape­marked the eighth successful landing on Mars in Nasa's history.

    Minutes after InSight landed on the surface of Mars, the first image was sent back, showing a wide flat area as seen through a dirty camera.

    The touchdown came after a nearly seven-month, 300 million-mile travel from Earth to Mars, during which the InSight spacecraft had to slow down from a speed of more than 12,000 mph. The spacecraft's heat shelter helped the lander survive temperatures as high as 2,700℉.

    Each step along the way was watched nervously at JPL, with updates delayed by the eight-minute light travel time between Earth and Mars. Mission controllers hugged each other with joy when the signals were received. "We are proud of everything that has gone on today," they told us reporters.

    The first picture of the surface of Mars was sent back to Earth by one of the MarCO nanosatellites (马可纳米卫星) that accompanied InSight during its travel to Mars. The dust from the landing made the view unclear. Pictures from it were expected to be clearer once the dust settled and the lens cover (镜头盖) was removed.

    Hours later, InSight's batteries were charging as expected. The InSight team also passed on another picture, taken by a different camera that's fixed on the lander's robotic arm. The view is clearer, showing the robotic arm and the seismometer, which is used to discover the actual movement of the ground.

New research into a long-lived tree has shown some of the tricks that have helped it survive for thousands of years. The ginkgo(银杏树) is a huge, slow-growing tree with fan-shaped leaves, native to China, but planted in parks and gardens across the world. Some of the largest ginkgoes are said to be more than 3, 000 years old.

In order to discover how these and other trees can live for so long, scientists from the US and China studied 34 healthy ginkgoes of different ages. The team studied growth rings in each tree's trunk(树干), as well as cells(细胞) from the bark, leaves and seeds. They found that 600-year-old trees were just as healthy as 2-year-olds.

To learn more, the team then looked in detail at the DNA of nine trees aged between three and 667 years old. DNA is the chemical in the cells of plants and animals that holds instructions that tell any living thing how to grow and develop-including what to do at different times in its life At the beginning of a tree's life, DNA instructs the cells in a seedling to divide quickly so the tree grows rapidly. The cells also make special chemicals to help the young plant survive difficult situations, such as disease. As most trees grow older, their DNA tells their cells to divide more slowly (so growth slows down) and to make fewer chemical defenses(防御).

Ginkgoes, however, do things differently. The team found that although their growth finally slows, both young and old trees make protective chemicals." The secret is keeping a really healthy defense system," said researcher Richard Dixon." As ginkgoes age, they show no sign of weakening their ability to defend themselves from things like disease. "Other trees that live for a long time may have the same ability.

For all their defenses, though, ginkgoes cannot live forever--they finally meet with deadly accidents such as fire, disease and storms. While they last, however, these leafy trees are some of the most beautiful trees in the world.