低碳合金结构钢用于渗碳件,中碳合金钢用于()和渗碳件,高碳合金结构钢用于制造较大的弹簧。
参考答案:调制件
地图反映了人们认识世界的程度,地图的变化记录了人们认识世界的过程。早期地图绘制者认为地球是平的,哥伦布等航海家则证实了地球是圆的,随着遥感技术的广泛应用,现在的世界地图日益精准,更好地满足了生产生活的需要。由此可见:( )
①认识只有不断超越历史条件才能成为真理 ②认识对实践具有依赖关系
③改造世界是认识的目的和归宿 ④事物的发展取决于认识的深化
A.①②
B.③④
C.①④
D.②③
- __________ that he managed to get the information? -Oh,a friend of his helped him. [ ]
A. Where was it
B. What was it
C. How was it
D. Why was it