An underground revolution begins this winter. With the flip (轻击) of a switch, 30,000 homes in one part of Detroit will soon become the first in the country to receive electricity transmitted by ice cold high performance cables. Other American cities are expected to follow Detroit"s example in the years ahead, which could conserve enormous amounts of power.
The new electrical cables at the Frisbie power station in Detroit are revolutionary because they are made of superconductors. A superconductor is a material that transmits electricity with little or no resistance. Resistance is the degree to which a substance resists electric current. All common electrical conductors have a certain amount of electrical resistance. They convert at least some of the electrical energy passing through them into waste heat. Superconductors don"t. No one understands how superconductivity works. It just does.
Making superconductors isn"t easy. A superconductor material has to be cooled to an extremely low temperature to lose its resistance. The first superconductors, made more than 50 years ago, had to be cooled to -263 degrees Celsius before they lost their resistance. Newer superconducting materials lose their resistance at -143 degrees Celsius.
The superconductors cable installed at the Frisbie station is made of a ceramic material that contains copper, oxygen, bismuth (铋), strontium (锶), and calcium (钙). A ceramic is a hard, strong compound made from clay or minerals. The superconducting ceramic has been fashioned into a tape that is wrapped lengthwise around a long tube filled with liquid nitrogen. Liquid nitrogen is super cold and lowers the temperature of the ceramic tape to the point where it conveys electricity with zero resistance.
The United States loses an enormous amount of electricity each year to resistance. Because cooled superconductors have no resistance, they waste much less power, other cities are watching the Frisbie experiment in the hope that they might switch to superconducting cable and conserve power, too.
单选题
What is the benefit of the revolution mentioned in the first paragraph?
【正确答案】
C
【答案解析】[解析] 细节题。本题可以通过定位选项来寻找正确答案。第一段的最后一句“Other American cities are expected to follow Detroit"s example in the years ahead, which could conserve enormous amounts of power.”意为“在未来几年，预计美国其他城市将遵循底特律的例子，能够节省大量的电力。”尽管A，B，D的内容都在第一段中被提及，但不是这场革命所带来的主要利益所在。所以选项C是正确答案。
单选题
Compared to common electrical conductors, superconductors ______.
【正确答案】
A
【答案解析】[解析] 细节题。利用题干关键词superconductors可以定位到第二段的第二句“A superconductor is a material that transmits electricity with little or no resistance.”意为“超导体是一种具有很少或没有电阻的导电材料”。所以选项A为正确答案。
单选题
At what temperature does the superconducting ceramic lose its resistance?
【正确答案】
A
【答案解析】[解析] 细节题。利用题干关键词superconducting和lose resistance可以定位到第三段最后一句“Newer superconducting materials lose their resistance at -143 degrees Celsius.”意为“新的超导材料的电阻在零下143摄氏度时失去电阻。”所以选项A为正确答案。
单选题
What element enables the ceramic tape to lower its temperature?
【正确答案】
B
【答案解析】[解析] 细节题。利用题干关键词lower the temperature可以定位到原文第四段第四句“Liquid nitrogen is supercold and lowers the temperature of the ceramic tape to the point where it conveys electricity with zero resistance.”意为“液氮提供超低温，能够降低陶瓷带的温度，使其导电零电阻”。选项A和D中的copper和calcium是用来制造超导体的陶瓷材料的成分；选项C中的clay是陶瓷材料的来源，所以选项B为正确答案。
单选题
According to the last paragraph, which of the following statements is NOT true?