承受预紧力F′的紧螺栓联接在受轴向工作拉力F时,剩余预紧力为F″ ,其螺栓所受的总拉力Fo为( ) 。
A campus emergency ______ occur at any time of the day or night, weekend, or holiday, with little or no warning.
免费的网站请分享给朋友吧