1 . Geothermal (地热的) power generation is one of our most stable renewable energy resources. Heat generated below the Earth’s surface can provide an almost unlimited supply to power and heat homes. And while geothermal electricity only accounts for around one percent of global generation, that is set to at least triple by 2050.
The Geysers in California is the world’s largest geothermal electricity complex. It produces enough electricity from its 18 power plants for 725,000 homes, totaling 20 percent of the state’s renewable energy. Superheated “dry steam” is channeled from a large sandstone reservoir heated by a large magma chamber (岩浆房) more than four miles beneath the surface.
Heat is captured from its passage through the rock and the heated water converts into electricity. Cooled water is then recycled and pumped back to gather more heat. EGS (enhanced geothermal systems) technologies will open up many more sites for geothermal energy. “You can effectively put a power plant anywhere,” said Will Pettit, director of the Geothermal Resources Council. “All you have to do is drill deep enough and you will find hot rock.”
Most geothermal plants actually use a flash steam technique, where hot water (at 360F or 180C) is drawn up, passed into lower pressure tanks and flashed into steam to power a turbine (涡轮机). Binary cycle (双元循环) plants are the growth technology because they can operate at lower water temperatures and more diverse geographical locations. They use moderately hot water to heat a secondary fluid with a lower boiling point—as low as 135F—to drive turbines.
Geothermal plants already emit 11 times less carbon dioxide per unit of electricity than the average US coal power plant. They can also operate 24 hours a day to provide a solid base load for homes and businesses.
There are drawbacks too. Seismic activity around drilling wells is a factor. High investment costs are another. But the US government is backing the sector with multi-million dollar funds to push forward advanced EGS research. Geothermal energy is set to play a big part in the low-carbon electricity future.
1. What is the significance of EGS (enhanced geothermal systems) technologies?| A．They have made geothermal energy less sustainable. |
| B．They have greatly reduced the need for drilling in geothermal sites. |
| C．They allow for more efficient use of geothermal resources. |
| D．They have opened up new methods of generating electricity from water. |
| A．Power plants are not affected by water. |
| B．Hot water is used to power a turbine directly. |
| C．Binary cycle plants are less restricted to sites. |
| D．A flash steam technique is a must in geothermal plants. |
| A．Perfect. | B．limited . | C．impractical. | D．promising. |
| A．Businesses have been competing to gain an advantage in geothermal power. |
| B．Geothermal power is likely to be a great chance to sustainable power. |
| C．Traditional power has been replaced by geothermal power in America. |
| D．EGS technologies have come into widespread application around the world. |
2 . The popular documentary series Aerial China (航拍中国) recently returned to the small screen. The latest and fourth season of it gives a perspective that is both excellent and informative. As the final of the series, the new season was shot across 11 provincial-level regions and started in the spring of 2020.
“The experience from the previous three seasons makes us more capable to follow wild animals while avoiding disturbing them,” says Yu, chief director of the series. China has made great efforts to protect endangered wildlife species and their habitats in recent years, and it has become much easier to spot rare species in the wild. Taking Tibetan antelopes as an example, the plateau-based creatures were difficult to encounter in the past, but the expansion of their population and enhanced research on their living patterns have allowed the camera crew to tailor plans to follow the animals.
Most close-ups for the season were shot by photographers from helicopters or cameras installed on drones (无人机). The vital moment for a successful shot depends on the mood of the animals or how good the weather is,” Yu says. In an attempt to fully show China’s huge changes over the past decade, the documentary series consulted experts from different fields to help select the most attractive shooting sites. In the final season, Aerial China has used 73 helicopters and 320 drones to shoot footage over an area of 900,000 kilometers, and selected around 1,000 staffers. More than 30 teams were assigned to shoot in different cities for the fourth season.
The previous three seasons have been watched by 850 million TV viewers and seen online over140 million times. For fans of the series, the director says he hopes that the new season will draw a bigger audience with its unusual perspective to show them China like never seen before.
1. Which can best replace the underlined word “perspective” in the first paragraph?| A．Reference. | B．Viewpoint. | C．Mention. | D．Standard. |
| A．To indicate a successful encounter. | B．To introduce new living patterns. |
| C．To show a biological improvement, | D．To save endangered wildlife species. |
| A．The team members’ roles. | B．The splendid shooting sites. |
| C．The hi-tech devices for shooting. | D．The efforts spent in the season. |
| A．This is the last but one season. | B．This season is well worth viewing. |
| C．The series is popular with TV reviewers. | D．The series is intended for Chinese fans. |
3 . 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. |
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. |
