【单选题】将金属材料加热到一定温度,保温后缓冷的热处理工艺称为 ()。
【单选题】退火工艺是将金属材料加热到某一规定温度,保温一定时间,而后( )冷至室温的一种热处理工艺。
【单选题】对女娲的故事的表达,蕴含的感情是:( )
【简答题】The rapid growth of cities worldwide over the next two decades will cause significant risks to people and the global environment, according to ysis. Researches from Yale and Stanford predict that ...
【单选题】In the opinion of a British editor, the richer cities tend to be more polite because people in the wealthier cities are better educated.