1 . The commonly held view is that people arrived in North America from Asia via a land bridge once connecting the two continents at the end of the Ice Age around 13,000 to 16,000 years ago. But recent discoveries have suggested humans might have been there earlier. Researchers studying fossilized human footprints in New Mexico say that humans were there at least 23,000 years ago.
Matthew Bennett, a specialist in ancient footprints and author of a study on the new findings published in Science, and his colleagues studied 61 footprints by radiocarbon(放射性碳) dating layers of aquatic (水生的) plant seeds preserved above and below the footprints and accurately dated they were made 21,000 to 23,000 years ago. The people who made the footprints were living there in the last Ice Age when two massive ice sheets covering the continent and cold temperatures would have made a journey between Asia and Alaska impossible, indicating humans must have been there much earlier than previously thought.
According to their analysis of the footprints, they were likely made in soft ground at the edge of a wetland by children who were sent to do the work like fetching and catching by adults. Wind probably blew dust over the surface, accumulating in the prints, thus, leaving footprints that previously recorded.
Their finding also makes it possible to explore the older and more controversial sites. One such site is Chiquihuite Cave in central Mexico, where stone tools dating back to 30,000 years ago have been found.
David Rachal, an experienced geoarchaeologist (地质考古学家) thought the footprint dates provided by Bennett and his team looked extremely solid, with seeds providing very reliable and precise ages through radiocarbon dating. “You could not ask for a better setup,” said Rachal. However, he was puzzled that no artifacts, such as stone tools, had been found in the area. “We need to be cautious and more research needs to be done.” Rachal said.
1. What is the most essential evidence dating the time in the passage?| A．The aquatic plant seeds. | B．The fossilized human footprints. |
| C．The unearthed tools. | D．The massive ice sheets. |
| A．To introduce a historical site. |
| B．To show the significance of the finding. |
| C．To compare geoarchaeological discoveries. |
| D．To explain the course of making a discovery. |
| A．Optimistic and trustful. | B．Conservative and cautious. |
| C．Negative but curious. | D．Favorable but confused. |
| A．The Discovery of Human Footprints. |
| B．Scientific Methods of Dating Footprints. |
| C．The Earlier Arrival of People in North America. |
| D．A Discussion on Human History Among Researchers. |
The Xi’an City Wall is the most complete city wall that has survived China’s long history. It
We accessed the wall through the South Gate. The wall is 12 meters high and from here you can see streams of people moving inside and outside the City Wall.
After
We
3 . America's Most Beautiful Places to Visit in Spring
Washington, D.C.
Every spring, Washington, D.C.is blanketed in pink with cherry blossoms. To celebrate the event, come to the National Cherry Blossom Festival, which takes place from the last week in March to the second week in April. You can view the flowers or take part in festival events.
Charleston, South Carolina
No list of beautiful spring cities would be complete without mention of Charleston, South Carolina. Delight in hanging plants, cobblestone streets, and historical castles. And because of year-round pleasant temperatures, you might even hit a beach day in March or April.
North Cascades National Park, Washington
The North Cascades is home to everything from mountains to forests to grassland, and the scenery changes seasonally. In spring—the snow disappears to bring strong waterfalls, and wildflowers spot the land. Different areas will present totally unique plants, so give yourself a few days to take in the sights.
Central Park, New York
New York is the city that never sleeps, no matter what the season, but springtime is the best time to take a walk through Central Park. It is one of the most filmed locations in the world. A spring time promises walks past Victorian houses, a brief visit to ancient shops, and of course long walks by the lake.
1. Which is the best time to visit Washington, D.C.?| A．March 15. | B．April 1. |
| C．March 8. | D．April 28. |
| A．cherry blossoms and various celebrations |
| B．pleasant weather and historical castles |
| C．strong waterfalls and wild flowers |
| D．Victorian houses, old shops, and long walks |
| A．Central Park, New York | B．North Cascades National Park |
| C．Charleston | D．Washington, D.C. |
4 . Famous Modern Chinese Buildings
Beijing International Airport
The first place most visitors see when they arrive in China is Beijing International Airport. The airport was constructed in the 1950s. It has an indoor garden, a children’s playground, and over 70 food businesses in Terminal 3 alone.
Shanghai World Financial Center
Completed in 2008, SWFC took over 10 years to complete due to financial shortages and construction delays. Since its completion, it has won countless architectural awards.
Tourists are welcome at SWFC's viewing platform, which at 474 meters above ground is the worlds highest closed viewing platform.
The Water Cube
It was constructed for use during the Beijing 2008 Summer Olympics. Now visitors can express surprise at the architecture of the building. They can enjoy the indoor atmosphere as well.
Among the offerings of the Water Cube are a restaurant and bar, a shopping area, and Water World, a family water park
The Bird's Nest, Beijing
It was designed mainly for the 2008 Summer Olympics. It can hold up to 80,000 people and has been used for a winter theme park. Nowadays, its main income is as a tourist attraction. It draws more than 20,000 tourists every day.
National Center for the Performing Arts
It was completed in 2007. The building is surrounded by a man-made lake, requiring guests to enter via an underground hallway. It is home to an Opera Hall, Music Hall, and Theater.
1. Which of the following buildings was first constructed?| A．Beijing International Airport. | B．Shanghai World Financial Center. |
| C．The Water Cube. | D．The Birds Nest, Beijing. |
| A．It needed more construction workers. | B．It was short of money. |
| C．It added an extra viewing-platform. | D．It faced too much terrible weather. |
| A．By renting the winter theme park. | B．By increasing its opening time. |
| C．By charging tourists for admission fees. | D．By giving some live concerts. |
| A．Enjoy sports events. | B．Play musical instruments. |
| C．Attend science lectures. | D．Watch different performances. |
