只有按照《电工进网作业许可证管理办法》（电监会15号令）的规定（）电工进网作业许可证的人，才能进网作业。 ["取得","注册","只要经过必要培训","取得并注册"]
Unfortunately, his father（）in the traffic accident yesterday. ["dead","was killed","killed","was dead"]
根据蒯因，（）可以帮助知识论成为心理学的一章。 ["生物学","进化论","科学","哲学"]
在客调能力标准化要求中，装移机工单进入综调系统之后，装维人员应在（）小时之内与用户联系响应。 ["半小时","1小时","2小时","4小时"]
简述水系的概念。
井下各种有害气体的允许浓度各为多少？
