Sleep is important to teenagers because it plays an important role in their physical and mental development. So how many hours of sleep does a teenager need?

A recent report shows that many teenagers in America are not getting the recommended amount of sleep. Here are the results.

Why is it hard for teens to get good sleep? There is no single reason. Instead, several factors (因素) relate to this problem. One of them is late bedtime and early school start times. Now, more and more teenagers are developing a habit of being “a night owl”, staying up later at night and sleeping longer into the morning. If allowed to sleep as they wish, many teens would get eight hours or more a night, but most school start times require them to wake up much earlier in the morning.

The use of electronic devices (设备) like the smartphone and computer is another factor. Research has found that 89% or more of teens keep at least one device in their bedroom at night. Screen time late into the evening can cause sleep problems. Using these devices can keep teens excited and unable to fall asleep. And being in the light from smartphones also makes people feel less sleepy.

So teens should improve their sleep environment and habits to get better sleep. Here are some tips.

◆ Get eight hours of sleep a night on weekdays and weekends.

◆Put away electronic devices at least half an hour before bed. ★

◆Keep the bedroom cool, dark and quiet.

What do you do with clothes you don’t want to wear anymore? You may donate them or give them to other people. What happens next? Where do these clothes end up?

It’s reported that 92 million tons of clothes end up in landfills every year. This means that every second a truck full of clothes arrives at a landfill.

Sadly, the beaches of Ghana, a country in West Africa, are one of these places. Now, the beaches are covered with clothing waste.

People from all over the world donate clothes to charity. However, charity shops only sell up 20 percent of donated clothes, said the Guardian. The unsold clothes are then put in large bags and travel to other countries to be sold again or treated as waste.

The Kantamanto market in Accra, the capital of Ghana, is one of the world’s largest secondhand clothing markets. Every week, 20 million pieces of clothes arrive at Kantamanto. But about 40 percent of them leave the market as waste.

Workers either burn the waste or put it underground. However, the city is near the sea, so there’s not enough space for landfills. This is why a lot of clothing waste ends up on the beach. As it goes into the sea, fish and other sea life are in danger. Sea turtles (海龟) can’t get to the land, and fish can’t grow because they may get caught in the clothes.

The waste is also hurting the economy (经济), Ernest Ijawan, a worker at a landfill in Ghana, told Forbes. Fishers can’t catch as many fish as before since most of the things they catch are clothes.

According to another survey, many fast fashion clothes are worn only 7 to 10 times, and then they are thrown away.

Around 15 years ago, this number was 10 to 15 times. People maybe haven’t realized that our clothes can be bad for the environment. But that’s the fact. So please think twice before we buy clothes or throw them away.

When was the last time you left home without your mobile phone? Can you imagine yourself living a month, or even a year without checking your mobile phone from time to time?

As a busy modern person with lots of social connections, plans and responsibilities, I just cannot afford to not be in touch with the rest of the world. Staying connected to other people is a big part of my life. However, sometimes it can be bothersome (恼人的).

One day I discovered I was terribly tired out. I tried turning notifications (通知) off. But the fear of missing out something important made me check the phone more often than before. So, I simply stopped using my phone.

To tell the truth, it was not simple at all. For the first couple of days, I had a big fear that all of my friends would soon forget about me. When I had a free moment, I had no idea what to get myself distracted (分心的) with, and the worries mixed with boredom kept bothering me.

However, after three weeks without a mobile phone, I started noticing changes—changes which I liked, and which drove me to not just continue the experiment, but in fact to reorganize some of my habits.

First of all, I noticed that I became much more focused (专注的). (A) Before, while doing something, I would often find myself wondering what was going on online. After a month of staying away from my mobile phone, I found that the urge (冲动) was already not that strong and that my ability to focus improved.

I discovered that the world is a beautiful place. Before, I would look at it through my camera mostly: take a photo, post it, get some likes. Now, I saw beautiful people walking around and I sensed the seasons change. I could understand the actual beauty of the world, and I did not need anyone else to prove the value of this beauty through likes or shares.

Now, as 100 days have passed, I can say that the experiment was worth it. I am planning to stay away from my phone for as long as possible.

Many traditional woodcut prints (版画) are either black and white or simple in color, but reduction woodcuts (绝版木刻) can show rich colors.

The reduction woodcut uses one piece of wood to make a colorful artwork. The artist cuts and prints different layers (层) in order on the same piece of wood. The reduction woodcuts became an intangible cultural heritage (非物质文化遗产) in Pu’er, Yunnan, in 2009.

Leng Guangmian, 40, is a reduction woodcut artist. Leng started learning it in 2003. He said that making reduction woodcut prints is just like an adventure. “Every time we cut on the wood and then print, we never know what it will be like in the end. “ As he sees beautiful patterns layer by layer, he only gets more excited, added Leng.

But finishing such work is not easy. He said that before cutting, he needs to plan for the whole print and choose colors for different layers. A big print usually takes months to finish.

Leng wants his artwork to show both great woodcutting skills and the culture and life in Pu’er. “For my works, there are two themes: Tea Horse Road (茶马古道), because Pu’er is one of the starting places of that road; and disappearing villages,” Leng said. “Many old villages in Pu’er need rebuilding, so I want to make people remember their beauty before (B) they are gone.”

Leng Guangmian is now getting more people to know about the reduction woodcut. He trains farmers in Pu’er and brings the art into schools. To make students understand and learn the art quickly, he even thought of a new idea of cardboard printing. “By using a small cardboard and making it simpler with three to five colors, students can get the beauty of the art,” Leng said.

56. 爱因斯坦曾说，在科学领域和艺术领域对真、善、美的不断追求，照亮了他的生 活道路，对艺术的爱好丰富和培育了他的感知力、想象力和创造力。艺术能够陶冶情操，美化心灵，涵养生命。生活中，也许是 a movie, a book, a song, a picture...曾经触动过我们的心灵。请结合自身经历，谈谈它是如何触动你的心灵的。