Steel is valued for its reliability, but not when it gets cold. Most forms of steel【C1】______become brittle (脆的) at temperatures

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问题    Steel is valued for its reliability, but not when it gets cold. Most forms of steel【C1】______become brittle (脆的) at temperatures below about -25℃ unless they are mixed with other metals. Now, though, a novel type of steel has been developed that resists【C2】______at much lower temperatures, while retaining its strength and toughness—without the need for expensive【C3】______.
   Steel’s fragility at low temperatures first became a major concern during the Second World War. After German U-boats torpedoed (用鱼雷攻击) numerous British ships, a 2,700-strong fleet of cheap- and-cheerful "Liberty ships" was introduced to replace the lost vessels, providing a lifeline for the【C4】______British. But the steel shells of hundreds of the ships【C5】______in the icy north Atlantic, and 12 broke in half and sank.
   Brittleness remains a problem when building steel structures in cold conditions, such as oil rigs in the Arctic. So scientists have【C6】______to find a solution by mixing it with expensive metals such as nickel.
   Yuuji Kimura and colleagues in Japan tried a more physical【C7】______. Rather than adding other metals, they developed a complex mechanical process involving repeated heating and very severe mechanical deformation, known as tempforming.
   The resulting steel appears to achieve a combination of strength and toughness that is【C8】______to that of modern steels that are very rich in alloy content and, therefore, very expensive.
   Kimura’s team intends to use its tempformed steel to make ultra-high strength parts, such as bolts. They hope to reduce both the number of【C9】______needed in a construction job and their weight—by replacing solid supports with【C10】______tubes, for example. This could reduce the amount of steel needed to make everything from automobiles to buildings and bridges.
   A) abruptly I) cracked
   B) additives J) fractures
   C) approach K) hollow
   D) ardently L) relevant
   E) besieged M) reshuffled
   F) channel N) strived
   G) comparable O) violent
   H) components
【C1】

选项

答案A

解析 副词辨析题。空格前面为主语most forms of steel,空格后面是系表结构become brittle,因此,空格处需要填入副词形式来修饰become brittle。本段第一句提到,钢的价值在于它的可靠性,但是当天气变冷的时候就不一样了。第二段第一句中的steel’s fragility更是明确提出了本篇短文的主题,即钢在寒冷气温下的易碎性,因此,此处是说大多数的钢在温度低于大约零下25℃时会突然变脆,容易破裂。由此确定副词A)abruptly“突然地”为本题答案。备选的另一个副词D)ardently“热烈地;热心地”与此处要表达的意思不符,故可排除。
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