1 . Wildfire, or wildland fire, is the uncontrolled fire occurring in a forest, grassland or bushlands.
Fire danger in a wildland setting varies with weather conditions: drought, heat, and wind. Once a fire is burning, drought, heat, and wind all increase its intensity. Topography(地形) also affects wildfire, which spreads quickly uphill and slowly downhill. Dried grass, leaves, and light branches are considered flash fuels, and fire spreads quickly in them, often generating enough heat to burn heavier fuels such as tree stumps(树桩), heavy branches, and the organic matter of the forest floor. Such fuels, ordinarily slow to burn, are difficult to extinguish. Green fuels—growing vegetation-are not considered to catch fire easily, but an intense fire can dry out leaves and needles quickly enough to allow ready burning. Green fuels sometimes carry a special danger. Evergreens, such as pine and spruce(云杉), contain oils that easily burst into flames when heated sufficiently by the searing drafts(灼热的气流) of a forest fire.
Firefighting forces are specially trained to deal with wildfires. Aircraft were first used in fighting wildland fires in 1919. Now airplanes and helicopters are primarily used for dumping water, for observation, and occasionally for assisting in communication and transporting personnel, supplies, and equipment
Tools for fighting wildfires range from the standard equipment of urban fire departments to portable pumps, tank trucks, and earth-moving equipment. It can also change the fire’s direction as well as slowing its progress. They are maintained by public and private owners of forestlands. Such a force may attack a fire directly by spraying water, beating out flames, and removing vegetation at the edge of the fire to contain it behind a fire line. When the very edge is too hot to approach, a fire line is built at a safe distance, sometimes using strip (长条地带) burning to get rid of the fuel in the path of the uncontrolled fire.
1. What is Paragraph 2 mainly about?| A．What causes wildfire to happen. |
| B．How topography affects wildfire intensity. |
| C．Why wildfire danger hides in green fuels. |
| D．Where wildfire often breaks out. |
| A．Carrying thin leaves. A. When the fire dies down. |
| B．Having heavy branches. |
| C．Lacking enough water. |
| D．Containing some oil. |
| A．When the fire dies down. |
| B．When the wind blows hard. |
| C．When the fuel burns uncontrollably. |
| D．When the pump works effectively. |
| A．An advertisement brochure. |
| B．A news report. |
| C．A sci-fi lecture, |
| D．A geography magazine. |
2 . Ho Khanh is a middle-aged farmer, living in a village on the edge of Phong Nha-Ke Bang National Park in Vietnam. What is special about him is that he has discovered Son Doong, the largest cave in the world.
“I first found the cave about thirty years ago, in 1991,” he says. “I was out collecting firewood near the national park. My family were very poor, so I decided to go deeper into the forest to find some aloe, which is very valuable. Not many people went that far into the forest because they were afraid of the wild animals.”
Soon Khanh lost his way. “I sat down with my back to a huge round rock,” he says. “Then I heard the sound of a strong wind and running water coming from behind me.” He found the entrance to a huge cave, with a wide river coming out of it. Khanh thought he was walking into a great cave. With no ropes or lights, he did not go further into it.
Khanh’s story spread like wildfire, but not everyone believed him. “I wanted to prove that I was telling the truth, but I couldn’t remember the way to the cave.” Then one morning early in the winter of 2006, a group of cavers from Britain came to ask Khanh for help, as they had heard about his discovery fifteen years before.
Khanh agreed to help the team to find the cave, but after three days in the jungle, they lost their way. “I just couldn’t remember where it was,” he says. The team came back twice, but each time they were beaten by the thick jungle. Finally the cavers left.
In 2009, Khanh headed to the jungle one cold winter’s morning. “I stopped by a big round rock,” he says. “There was the same strong wind, the sound of water running — I knew I’d found the cave at long last.” Soon the British cavers returned and followed Khanh on a six-hour trip deep into the jungle. On April 14 they found Son Doong.
1. What is the text mainly about?| A．How Son Doong was discovered. | B．How Son Doong got its name. |
| C．A young farmer in Vietnam. | D．A national park in Vietnam. |
| A．looking for aloe | B．collecting firewood |
| C．catching some animals | D．cutting down trees in the forest |
| A．They doubted it. | B．They believed it. |
| C．They were uncertain of it. | D．They had little interest in it. |
3 . The US government has recently helped people learn more about the dangers of earthquakes by publishing a map. This map shows the chances of an earthquake in catch part of the country. The areas of the map where earthquakes are most likely to occur are called earthquake belts. The government is spending a great deal of money and is working hard to help to discover the answers to these two questions:
Can we predict earthquakes?
Can we control earthquakes?
To answer the first question, scientists are looking very closely at the most active fault (断层) systems in the country, such as the San Andreas fault in California. A fault is a break between two sections of the earth’s surface. These breaks between sections are the places where earthquakes occur. But it will probably be many years before we can predict earthquakes correctly. And the control of earthquakes is even farther away.
However there have been some interesting developments in the field of controlling earthquakes. The most interesting development concerns the Rocky Mountain Arsenal earthquakes. Here water was put into a layer of rocks 4,000 metres below the surface of the ground. Shortly after this injection (注射) of water, there was a small number of earthquakes. Scientists have decided that the water which was injected into the rocks worked like oil on each other.
When the water “oiled” the fault, the fault became slippery and the energy of an earthquake was given out. Scientists are still experimenting at the site of these earthquakes. They have realized that there is a connection between the injection of the water and the earthquake activity. They have suggested that it might be possible to use this knowledge to prevent very big, dangerous earthquakes, that is, scientists could inject some kind of fluid like water into faults and change on a big earthquake into a number of small, harmless earthquakes.
1. Earthquakes belts are .| A．maps that show where earthquakes are likely to occur |
| B．zones with a high probability of earthquakes |
| C．breaks between two sections of the earth's surface |
| D．the two layers of earth along a fault |
| A．an active fault system |
| B．a place where earthquakes have been predicted correctly |
| C．a place where earthquakes have been controlled |
| D．at the foot of the Rocky Mountain |
| A．They occur at about 4.000 metres belowground level |
| B．The injection of water into earthquake faults prevent earthquakes from occurring. |
| C．They are usually caused by the oil in the faults. |
| D．Harmful earthquakes could be prevented by causing harmless earthquakes. |
| A．They have no practical value in earthquake prevention. |
| B．They may have practical value in earthquake prevention. |
| C．They are certain to have practical value in earthquake prevention. |
| D．Nothing is told about their practical value in earthquake prevention. |
4 . This summer we witnessed interview teams at the North Pole wearing short sleeve shirts due to the warm weather. A study published on Aug 29 revealed more concerning issues in the supposedly coldest area of the world. Zombie ice from a massive Greenland ice sheet was confirmed to be melting, which would eventually raise global sea levels by at least 10 inches (27 centimeters) on its own, reported Associated Press (AP).
Zombie ice is the kind of ice that is still attached to thicker areas of ice, but is no longer getting fed by larger glaciers. Since glaciers are getting less snow to complement the amount of ice melted, once the zombie ice is melted, it cannot be re-formed.
Scientists decided to look at the balance of the ice. In perfect equilibrium (平衡), snow in the mountains of Greenland flows down and thickens the sides of glaciers, balancing out what’s melting on the edges, according to AP. But in the last few decades, there is less refill and more melting, creating an imbalance.
Study co-author William Colgan told AP that 3.3 percent of Greenland’s total ice volume will melt eventually. “Starving would be a good phrase for what’s happening to the ice”, Colgan added.
With a great number of natural resources buried under the earth, areas of melted ice revealed treasures that attracted the world’s richest men. According to CNN, in early August, there was a “treasure hunt” in Greenland. Billionaires, including Bill Gates and others, financially backed KoBold Metals, a US-based mineral exploration company, to explore the rare metals under the glaciers in Greenland. The company told CNN that since there were enough minerals to power hundreds of millions of electric vehicles, the critical resource is capable of powering the green energy transition. While investors are taking advantage of global warming, experts feared that the mineral exploration is likely to worsen the local environment, draining up the world’s resources at a faster rate.
1. According to the text, what can we infer about zombie ice?| A．It’s complemented by nearby glaciers. |
| B．It will melt away from the ice cap. |
| C．It’s independent from large glaciers. |
| D．It has increased by up to 10 inches. |
| A．Why more zombie ice can’t be created. |
| B．How zombie ice is usually formed. |
| C．What the melting of zombie ice can lead to. |
| D．How zombie ice functions in the ecosystem. |
| A．The ice has brought about starvation. |
| B．The ice is refilled more than before. |
| C．The ice is becoming gradually thinner. |
| D．The ice has been good to skate on. |
| A．Supportive. | B．Tolerant. | C．Indifferent. | D．Worried. |
5 . In the 1960s, while studying the volcanic history of Yellowstone National Park, Bob Christian-sen became puzzled about something that, strangely, had not troubled anyone before he couldn’t find the park’s volcano. It had been known for a long time that Yellowstone was volcanic in nature—that is what accounted for all its hot springs and other steamy features. But Christian-sen couldn’t find the Yellowstone volcano anywhere.
Most of us, when we talk about volcanoes, think of the classic cone(圆锥体)shapes of a Fuji or Kilimanjaro, which were created when erupting magma(岩浆)piled up. These can form remarkably quickly. One day in 1943, a Mexican farmer was surprised to see smoke rising from a small part of his land. In one week he was the confused owner of a cone five hundred feet high. Within two years it had topped out at almost fourteen hundred feet and was more than half a mile-across. Altogether there are some ten thousand of these volcanoes on Earth, all but a few hundred of them extinct. There is, however, a second less known type of volcano that doesn’t involve mountain building. These are volcanoes so explosive that they burst open in a single big crack, leaving behind a vast hole, the caldera(火山口).Yellowstone obviously was of this second type, but Christian-sen couldn’t find the caldera anywhere.
Just at this time NASA decided to test some new high-altitude cameras by taking photographs of Yellowstone. A thoughtful official passed on some of the copies to the park authorities on the assumption that they might make a nice blow-up(放大的照片)for one of the visitors’ centers. As soon as Christian-sen saw the photos, he realized why he had failed to spot the caldera: almost the whole park—2.2 million acres -was a caldera. The explosion had left a hole more than forty miles across-much too huge to be seen from anywhere at ground level. At some time in the past Yellowstone must have blown up with violence far beyond the scale of anything known to humans.
1. What does the underlined word “its” in paragraph 1 refer to?| A．The ground. | B．The nature. |
| C．The volcano. | D．The park. |
| A．A single big crack was forming there. | B．Someone was burning stalks there. |
| C．A volcano was erupting underneath. | D．There were some hot springs there. |
| A．By looking at the photographs. | B．By analyzing its steamy features. |
| C．By researching historical documents. | D．By using some advanced equipment. |
| A．Its level is much higher than the surrounding areas. |
| B．The volcano in it involved mountain building. |
| C．It is a large hole left by the explosion. |
| D．Its shape is much like a cone. |
6 . The geographical location of a country and its physical characteristics are very important to its development and progress. The United States is very fortunate in this respect.
First of all, it has a good climate. In almost all sections of the country it is possible to live comfortably during the whole year. It is true that in the south it sometimes gets very hot, and in the north very cold. But the people who live in these regions become accustomed to the climate and never suffer very much when the weather is either very hot or very cold.
In a large country there is usually a great variety of different physical characteristics. In the United States, there are wide plains and high mountains, thousands of lakes and rivets of all sizes, cool forests and hot deserts, and a coastline several thousand miles long.
The many lakes and rivers, as well as the long coastline, have been of great importance to the development of the country, since they made possible the easy transportation of people and all the things people need. Transportation by water is still necessary and important. In modern times, however, trains, automobiles, trucks and airplanes are doing much of the work which was formerly done by ships and boats.
1. What are the principal physical characteristics of the United States?| A．Almost the same. | B．Rather various. |
| C．Very good for farming. | D．Suitable for transportation. |
| A．Geographical location. | B．Good climate. |
| C．Physical characteristics. | D．Both A and C. |
| A．They make the climate better. |
| B．They provide people with a good many opportunities of employment. |
| C．They provide people with good transportation and whatever they need. |
| D．They make the scenery of the country more beautiful and attractive. |
| A．Trains. | B．Trucks. |
| C．Planes. | D．Ships and boats. |
