What is the primary purpose for Digital Selective Calling (DSC)?（） ["DSC provides reception of weather and navigational warnings plus search and rescue information","DSC provides low-cost，routine communications for the vessel operator","DSC is to be used for transmitting and receiving distress alerts to and from other ships or coast radio stations via radio","This aids SAR authorities in tracking a vessel's position by satellite"]
依据华电集团《电力安全生产信息报送规定》，人身死亡、重伤事故，重大及以上设备、重大及以上火灾事故，事故报告待事故调查结束做出结论后（）天内报出。 ["2天","3天","5天","7天"]
采用多根导管浇筑水下混凝土时，导管的作用半径有何规定？
依据华电集团《电力安全生产信息报送规定》，一般设备事故、火灾事故发生后，应及时以电话、传真、电子邮件等方式，按资产关系或管理关系逐级汇报至集团公司，现场图片、书面文字等材料上报集团公司时间最迟不少于（）小时。 ["1小时","2小时","3小时","4小时"]
涉嫌传销当事人擅自动用、调换、转移、损毁被查封、扣押财物的，应受（）处罚。 ["责令停止违法行为","处被动用、调换、转移、损毁财物价值10%以上20%以下的罚款","拒不改正的，处被动用、调换、转移、损毁财物价值1倍以上3倍以下的罚款","不受处罚"]
当水下混凝土浇筑面积较大时，如何浇筑？
