"Are you going to Seattle?" an anxious-looking woman asked a femal traveler at the Amtrak Station in Sacramento, "No, I'm going to Eugene," the traveler replied. "Oh, I was hoping you could watch out for my daughter, she's never been on a train before."

Since I am a seasoned train traveler, I know that seats and cars are assigned by destination. So I approached the woman and her frightened-looking daughter and told them that her daughter could sit with me and that I would take care of her for the duration of the journey.

The train had arrived 25 minutes late, and people rushed to get their seat assignments. The conductor wanted to know if there were people traveling together, so I pushed my way to the front of the line with the girl and we were arranged to sit next to each other. Once on board, I showed her where to put her luggage, and took her to the bathroom area. We settled down to sleep. In the morning, she became comfortable enough to do what most 15-year olds do--talk and text on her mobile phone.

Throughout the trip, I made sure she picked up her ID, which had fallen out of her backpack, and generally kept an eye on her in an easy way. I hope someone takes her under their wing when she flies (another anxiety-producing first) back to Sacramento.

I do hope that kindness will spread around the world through these ways. We're conditioned to think that our lives revolved (旋转 )around great moments. But great moments often catch us unaware, beautifully wrapped in what others may consider a small one.

As the weather gets colder, we start wearing jackets, and most of us stop thinking about the sun. But the sun's rays can be just as harmful when it’s cold and cloudy outside. "Any exposed area of your body can still get sunburned," Dr. Apple A. Bodemer, an assistant professor at the University of Wisconsin-Madison, told Live Science.

Whether you spend a day on the slopes or clearing snow out of your driveway, your face is still getting exposed to the sun's radiation in the form of ultraviolet (紫外线)(UV) light, which can go deep into your skin cells, causing DNA damage, according to Bodemer.

The sun's long ultraviolet A (UVA) waves can cause earlier aging and wrinkles, while its shorter ultraviolet B (UVB) rays are known for causing skin reddening and bums.

Skin damage caused by UV exposure increases over time. More exposure to radiation contributes to severer damage, even skin cancer. In addition, snow and ice can also make sun damage worse. They reflect up to 80 percent of UV rays reaching the ground. That means you get heat from both the sky and the ground. And skiers and snowboarders increase their risk of getting sunburned even more because UV exposure increases at higher altitudes.

"Generally, the biggest factor for sun-sensitivity is how pale your skin is," Bodemer said. "But the reality is that even the individual with the darkest skin can get sun damage."

Luckily, the solution to protecting your skin is simple: Wear sunscreen every day. Rigel recommended using sunscreen with a sun protection factor (SPF) of at least 30, and that SPFs go higher at higher altitudes. As a rule of thumb, SPF 30 will block 97 percent of UVB rays, SPF 50 blocking 98 percent, and SPF 100 blocking 99 percent. Whatever kind of sunscreen you use, it's important to apply it once about every 2 hours.

Rigel also suggested sunscreens with "broad spectrum" — to protect against both UVB and UVA rays — as well as sunscreens that are water-resistant for up to 80 minutes. That way, you can go about your day without it wearing off too quickly.

Many people wrongly think that cities don't have farms and that fruits and vegetables are only grown in the country. Believe it or not, more and more urban farms are popping up in cities all over the world.

Alexandra Sullivan, a food system researcher in New York City, studies urban agriculture. Urban agriculture is another name for farming and gardening in a city environment. Ms. Sullivan studies everything from tiny gardens in empty lots between buildings to bigger fields that have been planted and grown. According to Ms. Sullivan, "Urban agriculture has existed since cities have, across the world."

The number of humans living in urban areas, or cities, is increasing. The amount of people who want to garden in urban areas is also rising. Ms. Sullivan says, "In small gardens, on rooftops and indoors, they grow fruits, vegetables, grains, and herbs, and raise animals to produce milk, eggs, honey, and meat. They use these foods as supplements to food produced by rural agriculture." Even though some people who live in urban areas grow crops, urban residents still need to rely on food grown in rural areas. This is because a city doesn't have enough space to grow enough food for everyone living in it.

In New York City, urban farmers have come up with many different ways to grow their own produce, even though there isn't a lot of room. For example, Brooklyn Grange is a farming operation that has two rooftop vegetable farms in New York City. All together, the farms are made up of 2.5 acres of rooftop space. This makes Brooklyn Grange one of the largest rooftop farming operations in the world.

Brooklyn Grange grows all kinds of things. The farming company sells its vegetables to local residents and restaurants. And because the farms are on rooftops, they are specially adapted to their urban location. They use available space that is not needed for anything else. As more urban farmers find ways to grow food in cities, urban residents will be better able to get fresher materials for their meals.

Many arguments teenagers have with their parents are about one thing: independence. As you get older, you’ll want to do more stuff on your own, without your mom and dad tagging along with you. The arguments generally start when your parents think you aren’t ready for extra responsibility while you think you are. Arguing with your parents isn’t the best solution at all, but the best solution is gaining trust from your parents.     16    

●Understand that it’s not your parents who do not want you to have independence, they want the best for you and think you’re not ready or you’ll hurt yourself if you have the freedom to do whatever you want. Show your parents you can be sensible.     17    If you can’t get home by 9:30, they’ll never let you out after 10:00.

●Agree with them some “friends time” and some “family time” so that they know you won’t be spending your whole weekend out with your friends.     18    They won’t imagine you getting into trouble if they know how they are.

●    19     They won’t feel much worried letting you go off on your own if they know what you’re up to. Call in and tell your parents that you’re OK from time to time. The less they worry about you, the more independence you’ll gain.

●    20    If they find out, all that trust will be destroyed and then you'll never get the extra independence you ever wanted.