钻井液中当Pm/Pf≥5时有()。 ["A、轻度的CO32-污染","B、严重的CO32-污染","C、没有污染","D、无法判断"]
穿引辘绳时应确保:() ①、滑车受力平衡;②、辘绳不相互磨擦;③、绞辘工作平稳,安全省力;④、根端按反时针方向穿引 ["①、②、③","②、③、④","①、③、④","①、②、④"]
()是整个欧洲文明的发源地,是古代奥运会的诞生地。 ["A、古希腊","B、古罗马","C、古埃及","D、古巴比伦"]
滑车轴,轴衬,挂头等构件磨损不得超过标准规格的:() ["1/5","1/10","1/2","1/20"]
企业战略管理的概念及特点?
企业宏观环境的构成?