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。
查看答案
虚作业是专用于化解“多重”作业的工具。
A. 对
B. 错
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()。
A. 特别重大事故
B. 重大事故
C. 较大事故
D. 一般事故
某公司是以重油为原料生产合成氨、硝酸的中型化肥厂,某日发生硝氨自热自分解爆炸事故,事故造成9人死亡、16人重伤、52人轻伤,损失工作日总数168000个,直接经济损失约7000万元。根据《生产安全事故报告和调查处理条例》,该起事故等级属于()。
A. 特别重大事故
B. 重大事故
C. 较大事故
D. 一般事故