简述虾维生素C缺乏病的诊断方法。
焦炉中气流由水平烟道分配至各支道时静压力应是() ["水平烟道外侧大","水平烟道中间大","水平烟道内侧大"]
对输送酸、碱以及易燃、易爆、有毒液体的泵,要求采用()轴封装置。 ["A.填料密封","B.液压密封","C.气压密封","D.机械密封"]
The required amount in the change of speed necessary before a governor will make a corrective movement is known as (). ["speed droop","sensitivity","stability","promptne"]
人员的培训与开发主要是针对两种人:一种是企业新录用的员工,另一种是()。 ["企业基层员工","技术骨干","企业现有员工","高层管理者"]
什么是联营公司?