Steel is valued for its reliability, but not when it gets cold. Most forms of

游客2024-03-11  4

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 [br] 【C7】

选项

答案 C

解析 名词辨析题。空格前面是形容词physical,且有不定冠词a修饰,因此,空格处应填入可数名词单数形式与a more physical一起作tried的宾语。下文提到,木村勇次及其同事采用了“反复加热和非常严格的机械变形”来加工钢材,这是一种物理加工方法,故空格处应填入一个表示“方式,方法”的名词。名词C)approach“方法,步骤”符合要求。其他备选的单数可数名词channel“频道;手段;海峡”和hollow“浅坑,凹陷处”均与此处语境不符,故排除。
转载请注明原文地址:https://tihaiku.com/zcyy/3524909.html
最新回复(0)