Joseph Francis Charles Rock (1884–1962) was an Austrian-American explorer, botanist, and anthropologist(人类学家). For more than 25 years, he travelled extensively through Tibet and Yunnan, Gansu, and Sichuan provinces in China before finally leaving in 1949.

    In 1924, Harvard sent Joseph Francis Rock on a treasure hunt through China's southwestern provinces—the Wild West of their day. But gold and silver weren't his task: Rock, a distinguished botanist, sought only to fill his bags with all the seeds, saplings, and shrubs he could find. During his three-year expedition, he collected 20,000 specimens for the Arnold Arboretum(阿诺德植物园).

    Botany, though, was just one of Rock's strengths. As an ethnologist(民族学者), he took hundreds of photographs of the Naxi, a tribe in Yunnan province, recording their now-lost way of life for both Harvard and National Geographic, and took notes for an eventual 500-page dictionary of their language. His hand-drawn map of his travels through China's “Cho-Ni” territory, in the Harvard Map Collection, includes more than a thousand rivers, towns, and mountains indicated in both English and Chinese, and was so well made that the U.S. government used it to plan aerial missions in World War II.

    Scientist, linguist, cartographer, photographer, writer—Rock was not a wallflower in any sense. Arrogant and self-possessed, he would walk into a village or warlord's place “as if he owned the place,” said Lisa Pearson, the Arboretum's head librarian.

    In declaring his successful return under the headline “Seeking Strange Flowers, in the Far Reaches of the World,” the Boston Evening Transcript ran a large photo of the daring explorer wearing in a woolly coat and fox-skin hat. “In discussing his heroism including hair-raising escapes from death either from mountain slides, snow slides and robber armies, he waves the idea away as if it is of no importance.”

    The Arboretum and Rock parted ways after 1927, mainly because his trip cost Harvard a fortune—about $900,000 in today's dollars. Fortunately, many of his specimens, many of his amazing photos, and his great stories remain.

    Can you imagine printing food? Some scientists are trying to revolutionize the dining experience by doing this. They hope that having a 3D printer in the kitchen will become as commonplace as the microwave. Scientists say that they are easy to use:you simply have to select a recipe and put the raw food "inks" into the printer. You can also change the instructions to make the food exactly how you want it. This means that it would be very quick and easy to create tasty and nutritious meals.

    They say that if people used 3D printers to create meals there would be less need for traditional growing, transporting and packaging processes as food production would be a lot easier. For example, alternative ingredients (原料) such as proteins from insects could be changed into tasty products. And as is known,those traditional activities are not beneficial to our surroundings.

    This technology could also help people who suffer from dysphagia (a swallowing disorder).The patients could program the printer and softer versions would be made so that they would not have trouble swallowing them.

    However,some people think that using 3D-printed foods would be a disaster. It could take away many jobs,including those for growing,transporting and packaging food. Imagine a world where there was no need for farming or growing crops and the same tastes could be printed from a raw "food ink". Likewise, traditional cafes and restaurants might lose business. Also, there are concerns about the nutritional value of printed food:is it really possible to get the nutrients we need from food-based inks?

    What's more, cooking and eating together with family and friends has long been a traditional and enjoyable activity. It is hard to imagine a world where the pastime of cooking is dead and meals can be created at the touch of a button.

    China's college graduates are leaving first-tier cities（一线城市）for second-tier ones, according to the annual College Graduates' Employment Report issued on Monday.

    The report said that 22.3 percent of college graduates last year chose to work in first-tier cities—Beijing, Shanghai, Guangzhou and Shenzhen—down 1.3 percentage points from 2016 and 5.9 percentage points from 2013. In 2017, 21.7 percent of college graduates chose to leave first-tier cities after working there for three years, up 2.5 percentage points from 2016 and 8 percentage points from 2015.

    The report also found that leading second-tier cities are attracting more recent graduates. Around 35.6 percent of college graduates who chose to work in the top 10 second-tier cities such as Hangzhou, Chengdu and Wuhan, were from other regions in 2017, up 3.6 percentage points from the previous year.

    The report was based on a survey of 306,000 graduates from 30 provinces and regions. It was released by MyCOS, an education consulting and research institute in Beijing.

    Wang Boqing, founder of MyCOS, said large populations, traffic jam, smog, increasing property prices and great difficulty in obtaining permanent residence（居住）, or hukou in Chinese, have brought high pressure to life in first-tier cities for college graduates, which gives second-tier cities an opportunity to attract talented workers.

    Second-tier cities have rolled out a series of policies to attract university graduates, which include favorable treatment to obtain hukou, as well as housing and government subsidies（津贴）, he said. Wuhan, Hubei Province, has planned to build affordable housing for university graduates, and allow graduates to buy or rent apartments at a discount of at least 20 percent of the market price.

    Chu Zhaohui, a senior researcher at the National Institute of Education Sciences, however, said that the governments of such cities should notice that welfare（福利）, housing and money can attract people in a short time. “Professionals aim mainly at prospects（前景）for career development rather than just benefits,” Chu said, adding that those cities should maintain their advantages, such as low cost of living and nicer environments, to keep their appeal. The cities should provide more opportunities for employment that are similar to those in first-tier cities, he said.

    Once an Englishman named Jack Brown went to Russia for a holiday. He stayed there for several months and then came home again. Some of his friends visited him a few days after he got back. "I had a very dangerous trip while I was in Russia," Jack said to them. "I wanted to see a friend of mine in the country and the bad weather made me very late. So I was still traveling through a forest in a sleigh(雪橇) when the sun went down. It was a long way from my friend's house when about twenty wolves began to follow my sleigh. It was very dark in the forest. There was thick snow on the ground. It was cold, and there were no houses for miles and miles. First I heard the wolves. The noise was terrible! The horses heard them, too. They were frightened and began running faster. Then I saw long, gray forms among the trees, and soon the wolves were near us. They were running very fast, and they didn't seem to get tired like the horses."

    "What did you do?" one of Jack's friends asked.

    "When the wolves got very near," Jack answered, "I put up my gun and shot the first wolf. The sleigh was moving about, but I hit the animal and killed it. Then all the other wolves stopped and ate it, so our sleigh got away from them for a few minutes."

    "Then they finished their meal, and I heard them coming again. The moon was shining brightly on the snow now, and after a few minutes I saw them running among the trees once more. They came nearer again, and then I shot another of them, and the others stopped once more to eat it."

    "The same thing happened again and again, and my horses became more and more tired and ran slower and slower until, after about two hours, only one wolf was still alive and following us."

    "Wasn't it too fat to run?" one of his friends asked.

5 Lifestyle Choices You Will Feel in Your Bones

    YOU SPEND TOO LITTLE TIME ON THE MOVE

    "Bone is a living tissue," says Jonathan Lee, a physician at Montefiore Health System in New York City. "The more you use it, the more it will adapt and strengthen. Likewise, if it is not subjected to loading, it will waste away. "The solution? Weight-bearing exercise-even just walking. Strength training Counts too

    YOU EAT SALTY SNACKS

    A study from Japan showed that women over fifty who had high sodium (钠) intakes were more than four times as likely to have a fracture (break of. bones)As those with low sodium intakes. That's because as the kidneys(肾) excrete(排出) the sodium, calcium is reducing from the bloodstream too.

    YOU SHUT SUNLIGHTAWAY

    "Vitamin D is required for the body to successfully absorb and use calcium," Dr. Lee says. "Most Americans do not get enough sun exposure to generate enough natural vitamin D, and thus supplementation is essential." According to the National Osteoporosis Foundation, adults under 50 need 400 to 800 IU of vitamin D daily and adults 50. And older need 800 to 1,000 IU. Talk to your doctor about your specific needs based on where you live, what time of year it is, and which vitamin D-rich foods you eat.

    YOU'RE CASUAL WITH WINE

    Low levels of alcohol consumption may be good for your bones, according to a study from Oregon State University, but more than a couple of drinks a day has the opposite effect. "Too much alcohol can make it harder to absorb calcium," says Dr. Lee. Furthermore, "In women in particular, higher alcohol consumption can decrease estrogen (雌激素) levels, and this can also lead to osteoporosis(骨质疏松), "Dr. Lee says.

    YOU LIVE INANAREA WITH DIRTYAIR

    In a study recently published in the Lancet Planetary Health, researchers dealt with hospital data for 9.2 million Medicare participants in the Northeast and mid-Atlantic between 2003And 2010. They found that even a small increase in levels of pollutants in the air--may lead to an increase in bone fractures and osteoporosis in older adults. If you live in a smoggy area, use an air purifier filter at home, avoid exercising outdoors when the air quality is bad, and get screened for osteoporosis.

Four Best Places to Travel for the Summer of 2019

    If you're still deciding where to take your summer vacation, 2019 brings major anniversaries, new flight routes, buzzy museum openings and more. In no particular order, check out our picks for where to travel this summer:

    Salar de Uyuni, Bolivia

    The Salar de Uyuni, or Uyuni Salt Flat, is a vast expanse near the Bolivian Andes that resembles ice. The surreal landscape is actually leftover salt from ancient lakes. A large lounge dome offers a public space with tables, floor cushions and hanging lanterns. Food is provided by Gustu in La Paz, considered one of Latin America's top restaurants. Beyond simply enjoying the food and scenery, guests can hike to the crater of Tunupa Volcano, mountain bike across the Salar or visit the village of Jirira. Come nightfall, on­site telescopes take full advantage of the star­flooded sky.

    Las Vegas

    There's the Park Theater, where up to 5,200 people can enjoy A­list artist residencies: Lady Gaga is currently in residence until November, with Janet Jackson and Cher starting this summer. For good measure, Bruno Mars will also be performing some dates in September. Daniel Humm and Will Guidara, perhaps best known for NYC's Eleven Madison Park restaurant, are behind the NoMad Restaurant and NoMad Bar. And foodies will no doubt want to experience Roy Choi's Best Friend, the first brick­and­mortar restaurant following his hugely successful Korean BBQ truck.

    Nova Scotia

    Nova Scotia often gets overlooked for popular provinces like British Columbia and Quebec, but its quiet charms are worth exploring. Cape Breton Island takes a bit of work to reach, but it's here that you'll find challenging hiking trails, a scenic driving route minus the traffic and real­deal Celtic culture. The Halifax Jazz Festival, held in the province's capital, is considered Nova Scotia's largest music festival, and goes down from July 9­14 on the waterfront.

    Grand Canyon

    It's the Grand Canyon's 100th anniversary as a national park, and there are multiple ways to celebrate this notable occasion. From June 22­29, stargazers can join amateur astronomers for free at the park's North and South Rims for the Star Party. Telescopes will be on hand to find planets (Jupiter and Saturn among them), star clusters and nebulae. There will also be slide show programs with a different focus each night, from protecting dark skies to learning how planets form. Constellation talks and night sky photography workshops are among the free offerings, just allow yourself enough time since you won't be the only one with this idea.