If a vessel under tow starts jumping on its tow line，the most appropriate action to alleviate the condition is to（）. ["change course","slow down","heave to","adjust tow line length"]
制造单位应当在许可证有效期届满（）个月前提出书面换证申请；经审查后，许可部门应当在有效期满前做出准予许可或者不予许可的决定。 ["1","2","3","6"]
宏站PMS系统立项阶段需由立项人员上传的文档为（） ["立项批复","可研\/立项方案会审纪要","项目可行性研究报告","可研批复"]
单相电容异步电动机，要其反转的方法有（）。 ["把主绕组或副绕组的首未端与电源线对调","把电容器从一绕组中改接到另一绕组中","把电源相、零线对调","把电动机转子重新安装"]
下列保险项目中的保险费只由用人单位缴纳的是（）。 ["养老保险费","工伤保险费","失业保险费","医疗保"]
在检修氮水预冷系统时，要注意哪些安全事项？
