Steel is valued for its reliability, but not when it gets cold. Most forms of steel 26 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 27 at much lower temperatures, while retaining its strength and toughness—without the need for expensive 28.
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 2700-strong fleet of cheap-and-cheerful “Liberty ships” was introduced to replace the lost vessels, providing a lifeline for the 29 British. But the steel shells of hundreds of the ships 30 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 31 to find a solution by mixing it with expensive metals such as nickel.
Yuuji Kimura and colleagues in Japan tried a more physical 32. Rather than adding other metals, they developed a complex mechanical process involving repeated heating and very severe mechanical deformation, known as temp forming.
The resulting steel appears to achieve a combination of strength and toughness that is 33 to that of modem 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 34 needed in a construction job and their weight—by replacing solid supports with 35 tubes, for example. This could reduce the amount of steel needed to make everything from automobiles to buildings and bridges.
A) abruptly
B) additives
C) approach
D) ardently
E) besieged
F) channel
G) comparable
H) components
I) cracked
J) fractures
K) hollow
L) relevant
M) reshuffled
N) strived
O) violent
答案解析：
26. 根据“Most forms of steel...become brittle (脆的) at temperatures below about -25℃ unless they are mixed with other metals.”可知这里说的是大多数钢在低温下会突然变脆，“abruptly”表示突然地，所以选A。
27. 根据前文提到钢在低温下会变脆，这里说新型钢能抵抗在更低温度下的“断裂”，“fractures”有断裂之意，所以选J。
28. 根据“without the need for expensive...”以及前文提到加其他金属，可知这里是不需要昂贵的“添加剂”，“additives”表示添加剂，所以选B。
29. 根据“providing a lifeline for the...British”可知是为英国人提供生命线，“besieged”有被围困的，这里表示处于困境中的英国人，所以29题选E。
30. 根据“and 12 broke in half and sank”可知很多船的钢外壳在北大西洋“裂开”了，“cracked”表示裂开，所以选I。
31. 根据“So scientists have...to find a solution”可知科学家努力找解决办法，“strive to do sth.”表示努力做某事，所以选N。
32. 根据“Rather than adding other metals, they developed a complex mechanical process...”可知他们采用了一种更物理的“方法”，“approach”表示方法，所以选C。
33. 根据“The resulting steel appears to achieve a combination of strength and toughness that is...to that of modem steels”可知这种钢达到的强度和韧性组合与现代钢“相当”，“be comparable to”表示与……相当，所以选G。
34. 根据“They hope to reduce both the number of...needed in a construction job”可知是减少建筑工作中需要的“部件”数量，“components”表示部件，所以选H。
35. 根据“by replacing solid supports with...tubes”可知是用“空心的”管子代替实心支撑，“hollow”表示空心的，所以选K。
