When asked to point out one or two things that are most important to themselves, many put friends ahead of homes, jobs, clothes and cars.

    A true friendship carries a long history of experience that determines who we are and keeps us connected. It is a treasure we should protect. Unfortunately, the better friends you are, the more probably you'll have disagreements. And the result can be what you don't want — an end to the relationship.

    The good news is that most troubled friendships can be mended. First, don't let your pride get in your way. Most of us can forgive each other when differences are brought out in the open. Second, apologize when you're wrong — even if you've been wronged. Over the course of a friendship, even the best people make mistakes. Sometimes, it may be best if the wronged person takes the lead and apologizes. When you apologize, give your friend a chance to admit(承认) that he has been wrong. Third, see things from your friend's point of view. And finally, accept that friendships change as our needs and lifestyle change. Making friends can sometimes seem easy. The hard part is keeping the connections strong during the natural ups and downs that have an effect on all relationships. My suggestion: consider friendship as an honor and a gift, and worth the effort to treasure and nurture(培养).

    It's been a hard time for rhinos (犀牛) lately. Recently the International Union for Conservation announced the western black rhinos had died out in the wild. It was last seen in western Africa in 2006. Now, those who work to protect the animals are trying to make sure that won't happen to other rhinos.

    19 south-central black rhinos in South Africa were driven to an area nearly 1,000 miles away, which was said to be the gentlest and quickest way to transport the animals. They were taken to a new home that would keep them safe from hunters.

    Though it is not allowed to hunt rhinos, many are still killed for their horns, which can sell for as much as $ 30,000 each. Most of them are used to make drugs as traditional medicines in Asian countries. Some people believe that the horns work well in treating pain, fever and even cancer. However, there is no medical evidence yet.

    Black rhino population began falling rapidly in the second half of the 1900s because of poaching. In fact, some people still hunt the animals at the risk of being put into prison. And many of the places where the animals used to live in were destroyed when people started building farms on the grasslands. Until the 1960s, about 65,000 black rhinos lived throughout most of Africa. Today, fewer than 5,000 are left—most of them in zoos and wildlife reserves.

    South Africa has the largest population of rhinos in the world. Poaching is an especially big problem in that country. So far, more than 340 rhinos have been killed there. Since 2003, the Black Rhino Expansion Project has been helping the south-central black rhinos in South Africa. The group works with landowners to find areas where rhinos can live safely away from hunters.

    So far, the group has successfully saved about 120 rhinos. Leaders of the project say the south-central black rhinos have seen a rise in numbers. It is hoped that, with continued support, these rhinos can escape the unfortunate result of the western black rhinos.

    Mexico sites on an island plateau (高原) surrounded by volcanic peaks, which makes air quality a constant concern for people who live there.

    In April, the country took a decisive step toward improving air quality by enacting a temporary ban on private and Federal vehicles in the city. The rule forbids people from driving in the city one day each week and one Saturday each month. Electric vehicles, government service vehicles, public transport options and school buses are not included in the ban.

    Mexico City isn't the first urban center to be involved in car-free living. But the ban is more than an awareness-raiser. It was enacted with the direct aim of solving air pollution. In March, the city sank into a deep brown haze of smog when the pollution levels passed the 200 mark. The city ordered some 1.1m of the area's 4.7m cars off the streets and also offered free bus and subway rides.

    Mexico City's temporary vehicle ban raises questions about the best ways to improve urban air quality. India, whose citizens breathe some of the world's dirtiest air, has tried a variety of solutions. Earlier this year, the Indian government started a 4% sales tax on new-car purchases.

    Beijing also has experience with cleaning the air. The city introduced alternate-day rules in advance of the 2008 Olympic Games, which produced good results. And then there is the London congestion (拥挤) charge, introduced in 2003. The charge has had a measurable effect on air quality.

For now, Mexico City — named by the United Nations as the most polluted city on the planet in 1992 — can look forward to the start of the region's rainy season, when daily showers will help lo clean the air.

    The US teenager Thomas Cheatham had planned to study Latin during his time at Hebron High School in Texas. But when he learned that the school district was going to offer a Mandarin class, he quickly changed his mind.

    “I thought Mandarin would be more beneficial than Latin,” said Cheatham, who is now in his second year of studying the language. He speaks Mandarin to order food at Chinese restaurants and can read social media posts from his Chinese-speaking friends.

    While it's a difficult language to master, the high school junior, who plans to study computer engineering, thinks it will be important for his career. “Chinese is a good language to know, especially with China becoming a growing power,” he said.

    Many experts agree that proficiency in a language spoken by a billion people worldwide will give American students an edge in the global economy. “People are looking at China as our next economic competitor, and interest in Mandarin is growing,” said Marty Abbott, executive director of the American Council on the Teaching of Foreign Languages. “We're seeing it in all parts of the country. ”

    Abbott estimates that as many as 100, 000 students are now studying Mandarin throughout the US, in public and private schools. She said the US government has designated (指定) Mandarin as a “critical needs” language and provides professional development programs for teachers. “Our government wants to increase our language competency for national security and economic competitiveness,” Abbott said.

    At the same time, the Chinese government is spreading knowledge of the Chinese language and culture through Confucius Institutes established in many US states. For example, the Confucius Institute at the University of Texas in Dallas has been the home of a Confucius Institute for 10 years. It sponsors Confucius Classrooms at 21 local public and private schools, where tens of thousands of students are learning Mandarin.

    We talk a lot in the U.S. about success. Success is the dream and the end point. And not by coincidence the idea that hard work leads to personal success is as American as apple pie.

    But the reality is that sometimes we fail. And sometimes things, through no fault of our own, don't go our way. We're faced with a life-changing diagnosis (诊断), the passing of a loved one or job loss. We don't, as a society, have as much to say here.

    I think uncertainty does us all harm. We'd feel better equipped to deal with uncertainty if we talked about it more. I had so fully bought into the belief that with enough effort, I could control what happened in my life. I actually caught myself thinking I could "work my way out" of my cancer. As it turns out, cancer doesn't really care about one's work.

    We might also make wiser decisions — this isn't just a feel-good exercise. For example, technology and medicine have progressed to the point that many patients are living longer than they would have even a decade ago. These are achievements worth celebrating. And yet I wonder if the focus on success is sometimes misguided here as well. If it is one reason why we tend to pursue expensive end-of-life treatments, they often accomplish little other than to make a patient's final days painful and frightening. The fact is that, when asked, many patients would rather focus on living meaningfully in their final days.

    My hope here is to make a case for thinking about meaning, in the same way we think about pursuing success. In that spirit, I've asked several people, each of whom has met misfortune, how they find meaning in their lives. The diversity in their responses reflects the fact that there are no right or wrong answers here. We each can find meaning in different things.

When I was three, my parents took me to have an operation in India, which stopped my eyesight from deteriorating(恶化). Several years later we moved to Pakistan, where I received 12 operations within one year and went completely blind. Later, I realized that the doctors used me as an experiment.

I met my husband when he came over from India to study. I wanted to go to India to marry him, but it was almost impossible to emigrate. I made a crazy plan to cross the borders of several countries to get to India. I was arrested in the first country I escaped to. Back in Pakistan, I lost my job and was asked to sign a "never-to-escape" promise. Instead, when I got home, I made a cup of coffee and decided to make a formal application for emigration. The chance was slim, and people who applied to go to India found it hard to find a job in Pakistan while they were waiting. In the end, my husband managed to smooth the way for my emigration. We got married and had children. But after nine years, he died of brain cancer. I was helpless for a while, and then I learned to face reality optimistically. He taught us happiness came from inside us.

Six years ago, I brought home a dog called Moritz from the seeing-eye dog centre. He was short with long ears. No one liked him because of his pathetic(可怜的)appearance. We were almost always together. Moritz could not leave me for even one minute. Now when I walk down the street, not like before, people will come up and say, "What a good seeing-eye dog! ", and have a little chat with me as a normal creature.

I'm now working for the Association of the Blind and I have many good friends, and a special friend in Hamburg. It is a wonderful feeling to speak freely with someone I can't see, to trust one another.