It was once common to regard Britain as a society with class distinction. Each class had unique characteristics.
    In recent years, many writers have begun to speak the 'decline of class' and 'classless society' in Britain. And in modern day consumer society everyone is considered to be middle class.
    But pronouncing the death of class is too early. A recent wide-ranging society of public opinion found 90 percent of people still placing themselves in particular class; 73 percent agreed that class was still a vital part of British society; and 52 percent thought there were still sharp class differences. Thus, class may not be culturally and politically obvious, yet it remains an important part of British society. Britain seems to have a love of stratification.
    One unchanging aspect of a British person's class position is accent. The words a person speaks tell her or his class. A study of British accents during 1970s found that a voice sounding like a BBC newsreader was viewed as the most attractive voice, Most people said this accent sounded 'educated' and 'soft'. The accents placed at the bottom in this study, on the other hand, were regional（地区的）city accents. These accents were seen as 'common' and 'ugly'. However, a similar study of British accents in the US turned these results upside down and placed some regional accents as the most attractive and BBC English as the least. This suggests that British attitudes towards accent have deep roots and are based on class prejudice.
    In recent years, however, young upper middle-class people in London, have begun to adopt some regional accents, in order to hide their class origins. This is an indication of class becoming unnoticed. However, the 1995 pop song 'Common People' puts forward the view that though a middle-class person may 'want to live like common people' they can never appreciate the reality of a working-class life.

阅读材料，回答下列问题。
    材料一 湄公河发源于中国青海省，注入南海，在中国境内称澜沧江，出境后称湄公河。澜沧江—湄公河流域资源丰富，人口众多，但经济社会发展水平并不高。
    材料二 受强厄尔尼诺的影响，2015 年底以来，澜沧江-湄公河流域遭受异常严重旱灾。中国于2016年3月15日开始经景洪水电站对下游实施应急补水，以帮助缓解旱情。为致力于区域经济社会的可持续发展，该流域各国在不同领域开展了广泛的合作。
    材料三  图1为澜沧江-湄公河示意，图2为流域内三城市的气候资料图。

图1                                图2

读我国四个重要的铁路枢纽示意图，分析以下说法正确的是（    ）

下列铁路干线是以省市区的简称来命名的是（    ）

已知，分别是四边形和的对角线，点在内，．
如图①，当四边形和均为正方形时，连接．
求证：；
若，，求的长；
如图②，当四边形和均为矩形，且时，若，，，求的值；
如图③，当四边形和均为菱形，且时，设，，，试探究，，三者之间满足的等量关系．（直接写出结果，不必写出解答过程）

读图，回答问题。

How Do You See Diversity?

　　As a manager, Tiffany is responsible for interviewing applicants for some of the positions with her company. During one interview, she noticed that the candidate never made direct eye contact. She was puzzled and somewhat disappointed because she liked the individual otherwise.
　　He had a perfect resume and gave good responses to her questions, but the fact that he never looked her in the eye said “untrustworthy,” so she decided to offer the job to her second choice.
“It wasn’t until I attended a diversity workshop that I realized the person we passed over was the perfect person,” Tiffany confesses. What she hadn’t known at the time of the interview was that the candidate’s “different” behavior was simply a cultural misunderstanding. He was an Asian-American raised in a household where respect for those in authority was shown by averting (避开) your eyes.
　　“I was just thrown off by the lack of eye contact; not realizing it was cultural,” Tiffany says. “I missed out, but will not miss that opportunity again.”
　　Many of us have had similar encounters with behaviors we perceive as different. As the world becomes smaller and our workplaces more diverse, it is becoming essential to expand our understanding of others and to reexamine some of our false assumptions.
Hire Advantage
　　At a time when hiring qualified people is becoming more difficult, employers who can eliminate invalid biases (偏见) from the process have a distinct advantage. My company, Mindsets LLC, helps organizations and individuals see their own blind spots. A real estate recruiter we worked with illustrates the positive difference such training can make.
　　“During my Mindsets coaching session, I was taught how to recruit a diversified workforce. I recruited people from different cultures and skill sets. The agents were able to utilize their full potential and experiences to build up the company. When the real estate market began to change, it was because we had a diverse agent pool that we were able to say in the real estate market much longer than others in the same profession.”
Blinded by Gender
　　Dale is an account executive who attended one of my workshops on supervising a diverse workforce. “Through one of the sessions, I discovered my personal bias,” he recalls. “I learned I had not been looking at a person as a whole person, and being open to differences.” In his case, the blindness was not about culture but rather gender.
　　“I had a management position open in my department; and the two finalists were a man and a woman. Had I not attended this workshop, I would have automatically assumed the man was the best candidate because the position required quite a bit of extensive travel. My reasoning would have been that even though both candidates were great and could have been successful in the position, I assumed the woman would have wanted to be home with her children and not travel.” Dale’s assumptions are another example of the well-intentioned but incorrect thinking that limits an organization’s ability to tap into the full potential of a diverse workforce.
　　“I learned from the class that instead of imposing my gender biases into the situation, I needed to present the full range of duties, responsibilities and expectations to all candidates and allow them to make an informed decision.” Dale credits the workshop, “because it helped me make decisions based on fairness.”
Year of the Know-It-All
　　Doug is another supervisor who attended one of my workshops. He recalls a major lesson learned from his own employee.
　　“One of my most embarrassing moments was when I had a Chinese-American employee put in a request to take time off to celebrate Chinese New Year. In my ignorance, I assumed he had his dates wrong’, as the first of January had just passed. When I advised him of this, I gave him a tong talking-to about turning in requests early with the proper dates.
　　“He patiently waited, then when I was done, he said he would like Chinese New Year off, not the Western New Year. He explained politely that in his culture the new year did not begin January first, and that Chinese New Year, which is tied to the lunar cycle, is one of the most celebrated holidays on the Chinese calendar. Needless to say, I felt very embarrassed in assuming he had his dates mixed up. But I learned a great deal about assumptions, and that the timing of holidays varies considerably from culture to culture.
　　“Attending the diversity workshop helped me realize how much I could learn by simply asking questions and creating dialogues with toy employees, rather than making assumptions and trying to be a know-it-all,” Doug admits. “The biggest thing I took away from the workshop is learning how to be more ‘inclusive’ to differences.”
A Better Bottom Line
　　An open mind about diversity not only improves organizations internally, it is profitable as well. These comments from a customer service representative show how an inclusive attitude can improve sales. “Most of my customers speak English as a second language. One of the best things my company has done is to contract with a language service that offers translations over the phone. It wasn’t until my boss received Mindsets’ training that she was able to understand how important inclusiveness was to customer service. As a result, our customer base has increased.”
　　Once we start to see people as individuals, and discard the stereotypes, we can move positively toward inclusiveness for everyone. Diversity is about coming together and taking advantage of our differences and similarities. It is about building better communities and organizations that enhance us as individuals and reinforce our shared humanity.
　　When we begin to question our assumptions and challenge what we think we have learned from our past, from the media, peers, family, friends, etc., we begin to realize that some of our conclusions are flawed (有缺陷的) or contrary to our fundamental values. We need to train ourselves to think differently, shift our mindsets and realize that diversity opens doors for all of us, creating opportunities in organizations and communities that benefit everyone.