铸件厚断面出现不规则孔眼,孔内壁粗糙是() ["A、气孔","B、渣眼","C、砂眼","D、缩孔"]
()是主管人员最基本的准则 ["有强烈的管理愿望","掌握大量的管理理论","以公司利益为准则","尽职尽责"]
熔炼铁液时加溶剂作用() ["A、溶铁","B、稀释熔渣","C、催化剂","D、提供热量"]
上层主管人员的重要任务是() ["监督执行 ","协调执行 ","监督控制 ","决策控制"]
金属型铸造比砂型铸造尺寸精度() ["A、高","B、低","C、相同","D、无法比较"]
设计双鞍座卧式容器时,支座位置应该按照那些原则确定?试说明理由。