测定灰分时，盛残渣的坩埚在775℃±25℃的高温炉中灼烧（），直到完全成为灰烬。 ["20min～30min","30min～45min","1.5h～2.0h","1h～1.5h"]
主叫手机在呼叫建立过程中，下面正确的空中接口信令顺序是（）。 ["Callproceeding－Setup－Alerting－Connect","Setup－Callproceeding－Alerting－Connect","Setup－Callproceeding－Connect－Alerting","Setup－Alerting－Callproceeding－Connect"]
资产回购协议和有追索权的资产销售，信用转换系数为（） ["0","20%","50%","100%"]
调车作业计划可分为（）。 ["编组计划","解体计划","变更计划","取送计划"]
I'm very sorry to have（） you with so many questions on such an occasion. ["interfered","offended","impressed","bothered"]
退火炉按降温曲线降温，当均热段温度下降到（）℃以下时，可停止供氮。
