题目内容
最初事件是惟一的，而最终事件却因作业结束时间不一致未必惟一。
查看答案
搜索结果不匹配？点我反馈
更多问题
PERT图中作业的开始事件的编号偶尔可以大于结束事件的编号。
虚作业是专用于化解“多重”作业的工具。
I. Blank-fillingearthquakes hub favorable ferryaccess chasing situated comfortableHong Kong, a small city crowded with seven million people, has been _____ after big dreams. _____ in the south east coast of China, it is a _____ for people from all over the world and is striving to be a first-class international city. Because of its pleasant weather, it is very _____ to live in Hong Kong. In addition, hardly is Hong Kong affected by natural disasters, such as _____ and tsunamis. The convenient public transport available in Hong Kong is another _____ condition for living. The railway system, as well as various means of transport including the bus, the mini-bus and the _____, links up all the districts in the region. Residents, therefore, gain easy and direct _____ to every corner of the city.
某煤矿发生瓦斯爆炸，救护队连续工作20多小时，先后发现28名人员遇难。次日寻找唯一1名失踪人员时，井下发生二次爆炸，造成5名救护队员死亡。根据《生产安全事故报告和调查处理条例》，这起事故的等级是（）。
微信支付 
支付宝支付