1 . Scientists recently discovered that pictures on cave walls at Creswell Crags are the oldest know in Great Britain. But they didn’t find in the usual way.

Archaeologists often date cave art with a process called radiocarbon dating. The technique can measure the age of carbon found in charcoal(木炭) drawings or painted pictures. Carbon is an element(成分)found in many things, including charcoal and even people. But in this case, there was no paint things or charcoal to test. People carve the pictures of animals and figure into the rock using stone tools. The scientists had an “aha!” moment when they noticed small rocks stuck to the top of the drawings. The small rocks must have formed after the drawings were made. “It is rare to be able to scientifically date rock art,” said Alistair Pike, and archaeological scientist at Britain’s University of Bristol. “We were very fortunate that some of the engravings (雕刻) were covered by stalagmites(石笋).”

When a test proved that the stalagmites formed 12,800years ago, the scientists knew the art underneath them had to be at least that old. And some of the animals shown, like the European bison, are now extinct, another tip-off (征兆) that the art is quite old.

The artists came to Creswell Crags. This place is one of the farthest points north reached by our ancient ancestors during the Ice Age. At that time, much of the North Sea was dry, so people could move about more easily.

Some tools and bones found there are 13,000 to 15,0000 years old. They show that the travelers hunted horses, reindeer, and arctic hares. Their artwork is similar to art in France and Germany. It tells scientists that the Creswell Crags artists must have had a close connection to peoples several thousand kilometers away---- another important evidence of understanding how humans spread out across the world.

According to the history, Chinese silk reached Rome before the time of Christ. Through the Silk Road, the Chinese culture     1     (introduce) to the Western countries and at the same time the Western culture came to the East.

As is    2     (know) to all, the Silk Road is a chapter    3     (record) the friendship between the European and Asian peoples. With a history of more than 2,000 years, the Silk Road in China can date back     4     the Han dynasty in ancient China. Though the Silk Road was mainly     5    trading route, it was    6     (benefit) to each other in the first place.In the following years in history, many great figures had made significant contributions to the development of the Silk Road. Today, the ancient Silk Road is more like a historical textbook for everyone to read and to learn     7     happened during ancient times. It    8     (actual) played a significant role in the development of the civilization of the world, opening long-distance political and economic    9     (communicate) between Europe and Asia.

Up to now, the Silk Road in China     10     (bring) great attraction to the tourism in China even in the world.

The Silk Road is in fact a    1    (relative) recent term. These ancient roads had no particular name     2     the mid-nineteenth century. Baron Ferdinand von Richthoften named the trade and communication network the Silk Road. Since then the term     3    (accept)globally.

In the nineteenth century, a new type of travelers stepped onto the Silk Road: archaeologists and geographers, enthusiastic explorers who were eager     4    (look) for adventure. Researchers who came from many countries traveled through the Taklamakan Desert,    5     is now in Xinjiang, to explore ancient sites along the Silk Road，    6    (lead) to many discoveries and studies, and most of all, a renewed interest in the history of these routes.

Today, many historic     7    (build) and monuments still stand, marking the passage of the Silk Road through hotels, ports and cities. What's more, the long-standing legacy of this     8    (impress) network is reflected in a large number of cultures, languages, customs and religions .The passage of merchants and travelers of many different nationalities resulted not only in commercial exchange,     9    in a widespread and continual process of cultural interaction. Obviously, it has become     10     driving force in the formation of diverse societies.

The Mayan civilization was from a group of people     1     lived in Central America. The Maya people used a(n)     2     (write) language before Columbus came to the Americas in 1492 AD. They were good     3     art, building, and math. They knew about stars and planets, which helped them make calendars.

The Mayan civilization was the most important between the years of 250 AD and 900 AD.     4     (gradual), the Mayan civilization spread all the way from Central Mexico to Honduras, Guatemala, and northern El Salvador.

The Maya people traded with other people in the Americas. They made changes to their buildings to make them much     5     (good). The style in which they made     6     ( they) buildings was often similar to styles of buildings in countries that the Maya people traded with.

The Mayan civilization started getting smaller after 900 AD. The Spanish arrived in     7     15th century and took over Central America, even in the Mayan areas. However, the Maya people still live there today. They even keep the old Mayan traditions and     8     (believe).There are many Mayan languages still spoken today,     9     (include) one called the Achi language. A play called Rabinal Achi     10     (consider) very important to the world.

6 . China is a country of many resources. Among its resources are many great rivers, which provide useful transport routes. Water transport is an efficient way to carry heavy loads, such as grain. In ancient times, a waterway was needed between China’s rich farmlands and the capital city. This need inspired engineers to build a canal. According to writings by the ancient thinker Confucius, work on a canal linking the Yangze River with the city of Huai-in began about 486 B.C. For many centuries afterward, Chinese emperors worked on extending this ancient canal.

This canal is now known as China’s Grand Canal. One thousand years after the original canal was begun, it was in extreme need of repair. This was in the year 607, during the Sui Dynasty. By 610 the emperor had had the canal extended. The Grand Canal formed a northeast-southwest link between the Yellow River in the north and the Huai River in the south. The canal remained the main waterway in this part of China for the next five hundred years.

In the thirteenth century, the Mongols had conquered China. The Yuan Dynasty established Beijing as the capital. The city’s growing population needed food, so a new canal was built to extend shipping. Building this part of the Grand Canal required enormous effort and cost. Neither the first attempt nor the second one was successful, so the builders chose another route. Finally this link in the Grand Canal was finished.

By the time of the Ming Dynasty, the Grand Canal had six sections. These were busy with goods until the nineteenth century. Then a series of severe floods struck China. Parts of the Grand Canal were badly damaged. By 1868 it had been largely abandoned as a means of northern route.

The Grand Canal was mostly restored in the twentieth century. It was widened and deepened, and a new section was constructed. Today the canal, which is about 1,200 miles in length, has new locks(运河的水闸). It is busy with ships and barges(驳船) carrying goods to and from cities along its banks.

7 . Who made the ABC song? Some people say a man named Charles Bradlee made the song. He was the first person to say he owned it. That was in 1834. Bradlee called the song “The Schoolmaster”. A schoolmaster is an old name for a teacher. No one knows where it came from. But we do have some clues.

The ABC song sounds the same as “Twinkle Twinkle Little Star”. It has the same tune, or music. It sounds like “Baa Baa Black Sheep”, too. Try singing each song. Sing them in a row. You can hear for yourself! The tune was first printed in 1761. It didn’t have any words. No one knows who wrote it. Later, a woman wrote the words for “Twinkle Twinkle Little Star”. Her name was Jane Taylor. She lived in England. She wrote the words in 1806. Mozart was a very famous composer. He wrote a piece of music in 1785. It sounds a lot like the ABC song!

When the ABC song first became popular, few children went to school. Most people did not learn how to read. They did not learn how to write, either. As time went on, this changed. More people needed to know how to read and write. More children started learning the ABC song. It helped them remember the letters.

Why do we sing the ABC song? We could just read it quietly. Or we could say it without singing. Why is the song partly important? The answer is related to how we learn. Children have always leaned from grown-ups. But 200 year ago, most people couldn’t read or write. Children had to remember things. They could not write down what they learned. They could not read about it later. So it was important to remember. Songs helped people remember. People sang songs that told stories. They taught their children what they knew through songs.

So, no none really knows who made the ABC song. We do know that this song is popular today. Most children who learn to speak English will sing it. Then they will remember their letters!

9 . Scientists recently discovered three tyrannosaur (霸王龙) trackways in Canada. The trackways suggest the meat eaters traveled and hunted in groups. The 70-million-year- old footprints are the first tyrannosaur trackways ever found.

Tyrannosaurs were a type of meat-eating dinosaur that included the strong Tyrannosaurus rex and Albertosaurus. “Groups of tyrannosaurs may have stuck together as a group to increase their chances of bringing down animals and individually surviving,” study coauthor Richard McCrea says. He works for Canada’s Peace Region Paleontology Research Centre. It’s believed that tyrannosaurs were solitary creatures. The newly discovered trackways could change the way scientists look at these frightening beasts.

Trackways can uncover a lot about the social behavior of a species. Unfortunately, very few tyrannosaur footprints have ever been found, and until recently, the only ones known were single prints discovered in Mongolia, the western U.S., and western Canada. But in October 2011, a hunting guide named Aaron Fredlund found two tyrannosaur track marks near Tumbler Ridge, an area in the foothills of the Canadian Rockies. Over the next year, McCrea and his team searched the site and found the remaining trackways.

The footprints are at about the same depth, which suggests the tyrannosaurs moved through the area at the same time. Impressions of the dinosaurs’ rough skin are even visible in the prints. The prints are also in near-perfect condition. That’s because the ground had a high clay (黏土 ) content when the dinosaurs walked through the area. The land was later covered by a thick layer of volcanic ash, which kept the marks intact (完整). “This is the most ideal situation you could ask for,” McCrea says.

Researchers aren’t sure of the exact species of tyrannosaur that left the prints. But the historic findings show a great deal about how the beasts moved and behaved. “We have extremely convincing evidence that tyrannosaurs traveled in groups,” says McCrea. “This is probably the most important evidence to come out to date on that topic.”