Languages have been coming and going for thousands of years, but in recent times there has been less coming and a lot more going. When the world was still populated by hunter-gatherers, small, tightly knit (联系)groups developed their own patterns of speech independent of each other.Some language experts believe that 10,000 years ago, when the world had just five to ten million people, they spoke perhaps 12,000 languages between them.

Soon afterwards, many of those people started settling down to become farmers, and their languages too became more settled and fewer in number. In recent centuries, trade, industrialization, the development of the nation-state and the spread of universal compulsory education, especially globalisation and better communications in the past few decades, all have caused many languages to disappear, and dominant languages such as English, Spanish and Chinese are increasingly taking over.zxxk

At present, the world has about 6,800 languages. The distribution of these languages is hugely uneven. The general rule is that mild zones have relatively few languages, often spoken by many people, while hot, wet zones have lots, often spoken by small numbers. Europe has only around 200 languages; the Americas about 1,000; Africa 2 400; and Asia and the Pacific perhaps 3,200, of which Papua New Guinea alone accounts for well over 800. The median number (中位数)of speakers is a mere 6,000, which means that half the world’s languages are spoken by fewer people than that.

Already well over 400 of the total of, 6,800 languages are close to extinction(消亡), with only a few elderly speakers left. Pick, at random, Busuu in Cameroon (eight remaining speakers),Chiapaneco in Mexico(150), Lipan Apache in the United States(two or three)or Wadjigu in Australia (one, with a question-mark): none of these seems to have much chance of survival.

  As cultural symbols go， the American car is quite young． The Model T Ford was built at the Piquette Plant in Michigan a century ago， with the first rolling off the assembly line （装配线）on September 27， 1908． Only eleven cars were produced the next month． But eventually Henry Ford would build fifteen million of them．

    Modern America was born on the road，behind a wheel． The car shaped some of the most lasting aspects of American culture： the roadside diner， the billboard， the motel，even the hamburger． For most of the last century， the car represented what it meant to be American﹣going forward at high speed to find new worlds． The road novel， the road movie， these are the most typical American ideas， born of abundant petrol， cheap cars and a never﹣ending interstate highway system， the largest public works project in history．

    In 1928 Herbert Hoover imagined an America with "a chicken in every pot and a car in every garage．" Since then， this society has moved onward， never looking back， as the car transformed America from a farm﹣based society into an industrial power．

    The cars that drove the American Dream have helped to create a global ecological disaster． In America the demand for oil has grown by 22 percent since 1990．

    The problems of excessive（过度的） energy consumption， climate change and population growth have been described in a book by the American writer Thomas L． Friedman． He fears the worst， but hopes for the best．

    Friedman points out that the green economy（经济）is a chance to keep American strength． "The ability to design， build and export green technologies for producing clean water， clean air and healthy and abundant food is going to be the curreney of power in the new century．"

Many of us love July because it’s the month when nature’s berries and stone fruits are in abundance. These colourful and sweet jewels from British Columbia’s fields are little powerhouses of nutritional protection.

Of the common berries, strawberries are highest in vitamin C, although, because of their seeds, raspberries contain a little more protein (蛋白质), iron and zinc (not that fruits have much protein). Blueberries are particularly high in antioxidants (抗氧化物质). The yellow and orange stone fruits such as peaches are high in the carotenoids we turn into vitamin A and which are antioxidants. As for cherries (樱桃), they are so delicious who cares? However, they are rich in vitamin C.

When combined with berries or slices of other fruits, frozen bananas make an excellent base for thick, cooling fruit shakes and low fat “ice cream”. For this purpose, select ripe bananas for freezing as they are much sweeter. Remove the skin and place them in plastic bags or containers and freeze. If you like, a squeeze of fresh lemon juice on the bananas will prevent them turning brown. Frozen bananas will last several weeks, depending on their ripeness and the temperature of the freezer.

If you have a juicer, you can simply feed in frozen bananas and some berries or sliced fruit. Out comes a “soft-serve” creamy dessert, to be eaten right away. This makes a fun activity for a children’s party; they love feeding the fruit and frozen bananas into the top of the machine and watching the ice cream come out below.

Teens and younger children are reading a lot less for fun, according to a Common Sense Media report published Monday.

While the decline over the past decade is steep for teen readers, some data in the report shows that reading remains a big part of many children’s lives, and indicates how parents might help encourage more reading.

According to the report’s key findings, “the proportion (比例) who say they ‘hardly ever’ read for fun has gone from 8 percent of 13-year-olds and 9 percent of 17-year-olds in 1984 to 22 percent and 27 percent respectively today.”

The report data shows that pleasure reading levels for younger children, ages 2-8, remain largely the same. But the amount of time spent in reading each session has declined, from closer to an hour or more to closer to a half hour per session.

When it comes to technology and reading, the report does little to counsel (建议) parents looking for data about the effect of e-readers and tablets on reading. It does point out that many parents still limit electronic reading, mainly due to concerns about increased screen time.

The most hopeful data shared in the report shows clear evidence of parents serving as examples and important guides for their kids when it comes to reading. Data shows that kids and teens who do read frequently, compared to infrequent readers, have more books in the home, more books purchased for them, parents who read more often, and parents who set aside time for them to read.

As the end of school approaches, and school vacation reading lists loom (逼近) ahead, parents might take this chance to step in and make their own summer reading list and plan a family trip to the library or bookstore.

Cities usually have a good reason for being where they are, like a nearby port or river. People settle in these places because they are easy to get to and naturally suited to communications and trade. New York City, for example, is near a large harbour at the mouth of the Hudson River. Over 300 years its population grew gradually from 800 people to 8 million. But not all cities develop slowly over a long period of time. Boom towns grow from nothing almost overnight. In 1896, Dawson, Canada, was unmapped wilderness(荒野). But gold was discovered there in 1897, and two years later, it was one of the largest cities in the West, with a population of 30,000.

Dawson did not have any of the natural conveniences of cities like London or Paris. People went there for gold. They travelled over snow-covered mountains and sailed hundreds of miles up icy rivers. The path to Dawson was covered with thirty feet of wet snow that could fall without warming. An avalanche(雪崩) once closed the path, killing 63 people. For many who made it to Dawson, however, the rewards were worth the difficult trip. Of the first 20,000 people who dug for gold, 4,000 got rich. About 100 of these stayed rich men for the rest of their lives.

But no matter how rich they were, Dawson was never comfortable. Necessities like food and wood were very expensive. But soon, the gold that Dawson depended on had all been found. The city was crowded with disappointed people with no interest in settling down, and when they heard there were new gold discoveries in Alaska, they left Dawson City as quickly as they had come. Today, people still come and go — to see where the Canadian gold rush happened. Tourism is now the chief industry of Dawson City — its present population is 762.

In the 1760s， Mathurin Roze opened a series of shops that boasted（享有）a special meat soup called consommé． Although the main attraction was the soup， Roze's chain shops also set a new standard for dining out， which helped to establish Roze as the inventor of the modern restaurant．

    Today， scholars have generated large amounts of instructive research about restaurants． Take visual hints that influence what we eat： diners served themselves about 20 percent more pasta（意大利面食）when their plates matched their food．  When a dark﹣colored cake was served on a black plate rather than a white one， customers recognized it as sweeter and more tasty．

    Lighting matters， too． When Berlin restaurant customers ate in darkness， they couldn't tell how much they'd had： those given extra﹣large shares ate more than everyone else， but were none the wiser﹣they didn't feel fuller， and they were just as ready for dessert．

    Time is money， but that principle means different things for different types of restaurants． Unlike fast﹣food places． fine dining shops prefer customers to stay longer and spend． One way to encourage customers to stay and order that extra round： put on some Mozart（莫扎特）．When classical， rather than pop， music was playing， diners spent more． Fast music hurried diners out．

    Particular scents also have an effect： diners who got the scent of lavender（薰衣草）stayed longer and spent more than those who smelled lemon， or no scent．

    Meanwhile， things that you might expect to discourage spending﹣"bad" tables， crowding．high prices﹣don't necessarily． Diners at bad tables﹣next to the kitchen door， say﹣spent nearly as much as others but soon fled． It can be concluded that restaurant keepers need not "be overly concerned about ‘bad' tables，" given that they're profitable． As for crowds， a Hong Kong study found that they increased a restaurant's reputation， suggesting great food at fair prices． And doubling a buffet's price led customers to say that its pizza was 11 percent tastier．