[问答题] 简述油罐呼吸阀挡板的节能原理。

长沙市在（）年跻身首批国家创新型试点城市？ ["2009","2010","2011","2012"] 简述劳动规章甜度评估的步骤。 在安装windows 2000 server时，可选择的磁盘分区文件类型有（）。 ["FAT","EXT","NTFS","FAT32"] 客户经理在营销履约保函时，下列哪项客户不得接受（） ["不能提供符合要求的反担保","具有完全民事行为能力的自然人","在华夏银行开立个人账户","具有真实、有效、合法的消费合同或经营合同，合同必须条款完备、责任明确"] The function of the bilge keel is to（）. ["reduce the rolling of the vessel","serve as the vessel's main strength member","add strength to the bilge","protect the vessel's hull when alongside a dock"] 简述油罐呼吸阀挡板的节能原理。