Excessive oil foaming in the crankcase of a refrigeration compressor is most likely to occur（） when the compressor. ["has continuously for a long period","suction pressure is below normal","oil level is below normal","starts after a long idle period"]
注入水的总含铁量应小于（）mg／L。 ["0.2","0.3","0.4","0.5"]
化学堵水施工时，车组、地面管线、管柱等能承受（）MPa的高压。 ["10","20","30","40"]
谈判者不是每次谈判都有七个信息，但是基本的谈判逻辑需要遵守的顺序是（）。 ["好的——坏的——大的——落实——收尾——稀释","收尾——坏的——大的——落实——稀释——好的","好的——大的——坏的——落实——稀释——收尾","好的——坏的——大的——落实——稀释——收尾"]
现浇砼柱支模高度9.8米，其模板超高次数（）。 ["1","2","3","4"]
礼品礼仪是指什么？
