【单选题】the boss for a raise didn’t do any good, so I am thinking of a shift to another company.
【单选题】the boss for a raise didn't do any good, so I am thinking of a shift to another company.
【单选题】将钢锭、铸件、锻坯加热至略低于固相线的温度,长时间保温,随炉缓慢冷却 的热处理工艺,称为 。
【单选题】我国电力的标准频率为 ( ) ,习惯上称为工频。日本、美国等国家的交流电的频率为( )。