1 . The Silk Road is arguably the most famous long-distance trade route of the ancient world. This passage connected Europe in the West with China in the East, and allowed the exchange of goods, technology, and ideas between the two civilizations. Although merchants could make huge profits travelling the road, it was not without risk.
The main Silk Road started in Chang’an (known today as Xi’an), the early Han capital. Travelers commencing their journey from this city could take a northern route that would take them across China’s northwestern provinces. After this, they would face the Gobi Desert, arguably the greatest danger of the Silk Road.
The Gobi Desert, the largest desert in Asia, consists mainly of rocky, hard earth. This feature made it easier for traders to travel across, compared to sandy deserts like the neighboring Taklamakan Desert. Like other deserts, the Gobi Desert is dry and hot, and therefore the biggest challenge travelers faced was obtaining enough water for themselves as well as for their camels.
So, rest stops were created along the route, allowing travelers to rest, eat and drink. These places also promoted the exchange of goods, and even ideas, amongst the travelers who stopped there. Usually, the rest stops were placed within a day’s journey of each other. In this way, travelers could avoid spending too much time in the desert, which would make them targets for robbers, another danger of the Silk Road.
Once through the Gobi Desert, travelers would continue their journey into Iran, Turkey, and finally Europe. While this part of the journey may have been less dangerous, it is not entirely without its perils (风险).
1. The underlined word “it” in the first paragraph refers to _________.| A．making huge profits | B．traveling the Silk Road |
| C．exchanging goods and ideas | D．connecting different civilizations |
| A．The desert’s surface was easier to walk on. |
| B．Camels for transportation were easier to find. |
| C．It was smaller and could be crossed in less time. |
| D．There were more natural water sources available. |
| A．Travelers were offered free accommodation. |
| B．They were located around the edges of the desert. |
| C．They were shared by travelers from different countries. |
| D．Exchanging goods and ideas there was entirely without risk. |
| A．The origins of the Silk Road. |
| B．The benefits of the Silk Road. |
| C．The difficulties faced by Silk Road travelers. |
| D．The cultural exchanges among Silk Road travelers. |
2 . The grass swung gently above a crack in the limestone (石灰岩) and Ludvik Husu realized he had found what he was searching for: a new cave in Slovenia’s dramatic Karst (喀斯特) region.
The cave enthusiast, with more than 50 years of experience, told AFP that “the conditions were perfect ... all the signs pointed to something beneath” as he felt the air current push up from below.
The 63-year-old had come across a new, 60-meter-deep limestone cave, a discovery that made the headlines this summer in a country that prides itself on its 14,000 underground caves.
The tiny Alpine nation is unusually rich in caves, which are a major tourist attraction. Perhaps the best known is the Postojna cave system, the longest in Europe, discovered by another amateur enthusiast two centuries ago. It extends for 24 kilometers and has offered up valuable finds for biologists.
Stanislav Glazar, a Postojna cave guide, told AFP that more than 150 species have been discovered in the system.
Glazar said Postojna is one of the richest caves in the world “in limestone formations.” The cave, located about 50 kilometers south of the capital Ljubljana, was also home to the world’s first cave tourist train, which began transporting visitors in 1872.
Elsewhere in the Karst region, the cave systems are of historical, cultural and even extraterrestrial interest. For instance, the UNESCO-listed Skocjan system was where the European Space Agency sent some astronauts to prepare for life in space.
“Astronauts know that the Karst world is exceptional, in a similar way to the environment in space: you don’t know what to expect at your next step,” said Skocjan Caves director Tomaz Zorman.
But for Husu, it’s the exploration that proves most rewarding. Once he knows there is something beneath, he digs around the crack to widen it and alerts fellow cavers to help gain access. He then uses ropes and a lamp to go down to what are vertical entrances in most caves. But doesn’t he feel scared to enter such unexplored depths?
“You enter a cave out of curiosity — there is no fear! Those who feel fear should stay home,” he said.
1. What was people’s attitude towards Ludvik Husu’s new finding this summer?| A．Critical. | B．Positive. | C．Doubtful. | D．Indifferent. |
| A．It has little biological value. |
| B．It has diverse limestone formations. |
| C．It is the most famous cave system in Europe. |
| D．It has been open to the public for two centuries. |
| A．Financial. | B．Political. | C．Alien. | D．Biological. |
| A．Slovenia is known for its Karst landforms. |
| B．Ludvik Husu started exploring caves before he was 13. |
| C．Slovenia has the most underground caves in the world. |
| D．Ludvik Husu is often upset about entering unexplored caves. |
3 . Mapping Antarctica
Antarctica was on the map long before anyone ever laid eyes on it. Nearly 2,400 years ago, ancient Greek philosophers such as Aristotle believed that a great continent must exist at the bottom of the world. They though it was needed to balance out the continents at the top of the world. In the 1500s, mapmakers often included a fanciful continent they referred to as Terra Incognita(Latin for “unknown land”) at the bottom of their maps. But it was not until the 1800s -----after explorers had sighted and set foot on Antarctica----- that mapmakers got down to the business of really mapping the continent, which is one—and—a –half times rhe size of the U.S..
While the coastline could be mapped by ships sailing around the continent, it took airplanes—and later, satellites---to chart Antarctica’s vast interior(内陆). That job continues today. And it is a job that still require a mapmaker, or cartographer, to put on boots and head out into the wild.
Cole Kelleher is familiar with that. He is a cartographer with the Polar Geospatial Center(PGC), which is based at the University of Minnesota and has a staff at McMurdo Station. PGC teamed up with Google to use the company’s Trekker technology to capture images of Antarctica for the Internet giant’s popular feature, Street View. A Trekker camera, which is the size of a basketball, is set about two feet above a backpack. The camera records image in all directions. “It weighs about 50 pounds. I was out for two and a half days, hiking 10 to 12 hours each day,” says Kelleher. It was hard work, but really an incredible experience.” According to Kelleher there are plans to use the technology to create educational apps for museums.
The PGC staff at McMurdo Station provides highly specialized mapmaking services for the U.S. Antarctic Program. For one project, Kelleher used satellite images to map huge cracks in the ice. That helped a team of researchers know whether they could safely approach their field camp on snowmobiles. Another recent project was to help recover a giant, high—tech helium(氦气) balloon used to carry scientific instruments high into the atmosphere. These balloons are launched in Antarctica because there is no danger that they will hurt anyone when they fall back down to Earth. Using satellite images, Kelleher and colleagues created maps of where the balloon could be found.
Antarctica may no longer be Terra Incognita, but it still holds countless mysteries. Cartographers and the maps they make will continue to be essential in helping scientists unlock those secrets.
1. From the passage, we can infer that Antarctica was on the map in the 1500s when________.| A．mapmakers knew it was much larger than the U.S. |
| B．Aristotle named the continent Terra Incognita |
| C．no one had ever seen or been to the continent |
| D．it was such an interesting continent as was often referred to |
| A．It needs much work for the mapmakers to head out into the wild. |
| B．The interior can only be mapped by planes and satellites. |
| C．It is relatively easy to map Antarctica’s coastline by ship. |
| D．Antarctic is a vast but still mysterious continent. |
| A．to capture images of Antarctica for Street View |
| B．to test the company’s Trekker technology |
| C．to create educational apps for museums |
| D．to hike for an incredible experience |
| A．satellite images which are used to map huge cracks in the ice |
| B．a high-tech helium balloon for carrying scientific instruments |
| C．how to safely approach the researcher’s field camp and the balloon |
| D．the specialized mapmaking services provided by the PGC staff |
4 . By the end of the century, if not sooner, the world’s oceans will be bluer and greener thanks to a warming climate, according to a new study.
At the heart of the phenomenon lie tiny marine microorganisms(海洋微生物) called phytoplankton. Because of the way light reflects off the organisms, these phytoplankton create colourful patterns at the ocean surface. Ocean colour varies from green to blue, depending on the type and concentration of phytoplankton. Climate change will fuel the growth of phytoplankton in some areas, while reducing it in other spots, leading to changes in the ocean’s appearance.
Phytoplankton live at the ocean surface, where they pull carbon dioxide(二氧化碳) into the ocean while giving off oxygen. When these organisms die, they bury carbon in the deep ocean, an important process that helps to regulate the global climate. But phytoplankton are vulnerable to the ocean’s warming trend. Warming changes key characteristics of the ocean and can affect phytoplankton growth, since they need not only sunlight and carbon dioxide to grow, but also nutrients.
Stephanie Dutkiewicz, a scientist in MIT’s Center for Global Change Science, built a climate model that projects changes to the oceans throughout the century. In a world that warms up by 3℃, it found that multiple changes to the colour of the oceans would occur. The model projects that currently blue areas with little phytoplankton could become even bluer. But in some waters, such as those of the Arctic, a warming will make conditions riper for phytoplankton, and these areas will turn greener. “Not only are the quantities of phytoplankton in the ocean changing. ” she said, “but the type of phytoplankton is changing.”
And why does that matter? Phytoplankton are the base of the food web. If certain kinds begin to disappear from the ocean, Dutkiewicz said, “it will change the type of fish that will be able to survive.” Those kinds of changes could affect the food chain.
Whatever colour changes the ocean experiences in the coming decades will probably be too gradual and unnoticeable, but they could mean significant changes. “It’ll be a while before we can statistically show that the changes are happening because of climate change,” Dutkiewicz said, “but the change in the colour of the ocean will be one of the early warning signals that we really have changed our planet.”
1. What are the first two paragraphs mainly about?| A．The various patterns at the ocean surface. |
| B．The cause of the changes in ocean colour. |
| C．The way light reflects off marine organisms. |
| D．The efforts to fuel the growth of phytoplankton. |
| A．Sensitive. | B．Beneficial. | C．Significant. | D．Unnoticeable. |
| A．Phytoplankton play a declining role in the marine ecosystem. |
| B．Dutkiewicz’s model aims to project phytoplankton changes. |
| C．Phytoplankton have been used to control global climate. |
| D．Oceans with more phytoplankton may appear greener. |
| A．To assess the consequences of ocean colour changes. |
| B．To analyse the composition of the ocean food chain. |
| C．To explain the effects of climate change on oceans. |
| D．To introduce a new method to study phytoplankton. |
