时效处理、冰冷处理的目的?
参考答案:
时效目的:是淬火攻坚,慢慢消除内应力而稳定其形状尺寸.
冰冷处理的目的:减少合金组织中参与的奥氏体,以增高硬度和耐磨性。
The chief editor asked me to write one more article for their newspaper, is about the wages of the farmer workers.
A.that
B.which
C.one
D.it
儿童缺锌的主要表现为()
A.食欲不振
B.厌食
C.免疫力低下
D.生长发育不良
E.性成熟推迟