Condensate must be drained periodically from the air compressor receivers to prevent (). ["second stage cylinder lockup","oil sump contamination","faulty operation of pneumatic valves","corrosion of air receiver baffle"]
柏拉图的《大希庇阿斯》一篇关于“美”的结论是() ["美是恰当","美是视觉和听觉的快感","美是难的","以往关于美的定义各有所长"]
《北京市实施办法》于2015年11月27日审议通过,于()正式施行。 ["2015年11月27日","2015年12月31日","2016年1月1日","2016年6月1日"]
下列属于终止密码子的是哪些?() ["AUG","UAA","UGA","UAG"]
Overheating of a hydraulic system may be a result of (). ["changing pump discharge pressure in response to normal load variations","a high oil level","incorrect fluid viscosity","continued slow re-circulation of the oil"]
会展项目控制有哪些方面的作用?