Steel's fragility at low temperatures first became a major concern during the Second World War.

第二次世界大战期间，钢材在低温下的易碎首次成为人们关注的重点。

Brittleness remains a problem when building steel structures in cold conditions, such as oil rigs in the Arctic.

在寒冷条件下建造钢材结构，比如北极地区的石油钻塔，钢的易碎是一个问。

However, RCT permanently deprives vitality and sensitivity from thetooth, consequently increasing the friability of the remaining tooth.

而, RCT永久地剥夺了牙齿的活力和敏感, 从而增加了剩余牙齿的易碎。