At schools across the United States, students often sit down to school lunches made from foods that are high in fat and sugar. But kids at Public School (P.S.) 216 have a different dining experience.Head teacher Donna Neglia reports that her students “love eating fresh fruits and vegetables”.

P.S.216 takes part in the Edible Schoolyard Project, a program started by Alice Waters in 1995. It helps public schools across the country start on­site gardens. Students grow and care for crops, harvesting (收获) the fruits and vegetables for school meals.

In a recent interview, Waters advised schools to “connect with the farmers in their area, and change their buying practices” when planning meals for students. “Instead of having a hot dog or a pizza that comes from a fast­food restaurant,” she said, “schools should buy a real hot dog that is organic (有机的), and they should buy a pizza from somebody who cares about where that foods come from.”

The students and teachers at P.S.216 work together to keep a garden and farm in the middle of New York City. “Students are happily involved in all of the most important tasks,” said teacher Cecilia Galarraga, “including watering, planting, harvesting, etc.”

Through the Edible Schoolyard Project, students also learn about the advantages of healthy eating in the classroom.Neglia said that P.S.216 is teaching kids about “careers in the food industry—such as farming, food safety, and the restaurant business”.

Similar classes are taking place around the country. So far, the Edible Schoolyard Project has reached more than 1 million students in more than 360 schools.

“I’m thinking about the future of the planet,” Waters said. “I’m doing this for the young generation.”

What do extreme marathoners, mountain hikers and professional bicycle racers all have in common? They push their bodies to unsustainable (不可持续的) extremes of physical stress.

We tend to think there’s no limit to human physical achievements. But a new study, published in Science Advances, says there is a definite limit to human endurance (耐力). Beyond that, our bodies begin to break down.

To find the limit, a US research team tracked marathon runners over a five-month period, measuring competitors’ initial basal metabolic rates (BMR, 基础新陈代谢率) – the amount of energy they expend when they rest. Then they looked at how many calories(卡路里) each runner burned per day.

The team found that the maximum amount of energy a human can expend is 2.5 times of BMR. It equals 4,000 calories of energy per day. These calories can help a trained athlete to run about 42 kilometers in a day.

But people can’t keep using this amount of calories all the time. “You can do really intense stuff for a couple of days, but if you want to last longer then you have to dial it back,” US evolutionary anthropologist Herman Pontzer told the BBC.

Pontzer explained that the problem is our guts (消化道). “There’s … a limit to how many calories our guts can effectively absorb per day,” he said in the Daily Mail. At that point, the body is burning calories more quickly than it can absorb food and convert (转化) it into energy.

These new findings could help athletes to best work underneath this ceiling. For example, they could manage their daily exercise time based on their BMR, to get enough calories and keep going.

However, Pontzer’s team can’t rule out the possibility of someone breaking this limit. “So I guess it’s a challenge to elite endurance athletes,” said Pontzer. “Science works when you’re proven wrong. Maybe someone will break through that ceiling some day and show us what we’re missing.”

For a single woman, yards are a strange thing. You don’t know whether to buy a lawn mower(割草机)or hire someone to mow it. I did the latter, over many years.

There was one exception. In my early 30s，I lived in a cottage near my father, who had a tractor. He lived around the corner on an old country lane, now fully developed. But at the time, it was with sweet relief, having just returned from city life, that I drove his borrowed tractor down the lane in the late afternoon, mowed my land, and then drove it back in the evening light, gazing(注视)up at the stars as they came out.

Soon the routine became impossible with traffic in the developing area. I needed someone to do my yard work.

Vardman was a devoted young boy. He sang at the top of his lungs as he mowed. His work was a joy. But Vardman grew up. After his graduation from high school, which I attended, and his leaving for college, I was without.

So here I was with two African men who brought not only knowledge but a deep love of working the land. There was a peace about the work they did. The perfection was noticeable everywhere, with every border in place, the unnecessary brush cleared out. The rhythm in their work, the rhythm of their work—it was poetry to watch.

Later I moved to North Carolina. I found myself in another small house with a beautiful but wasted yard. A strange mountain man gave me a wonderful price and began what has become an exercise in grace, gratitude and being simple.

Over the few years I have lived here, he has slowly, patiently, lovingly turned a long-neglected place into a quiet beauty. Quiet, modest, sincere, he uses only natural products on the lawn and flower beds. After the growing season ends, he collects his final paycheck and disappears into the mountains. A quiet man is teaching me patience and how it brings beauty back.