哪两个国家是世界上从事粒子束武器技术研究的主要国家。()
A.中国
B.美国
C.英国
D.苏联
参考答案:B, D
All the following statements regarding creating of time estimates are correct EXCEPT:
A.Mathematical analysis like CPM, GERT and PERT indicate the dates in which the activity can be scheduled given resource limits and other constraint
B.Duration compression techniques including fast tracking and crashing can help in decreasing the project schedul
C.WBS classification allows for useful activity ordering and sortin
D.The duration of the project is the sum of durations for all the tasks in the projec
融化琼脂印模材料最为方便的方法是
A.微波炉中解冻融化
B.电炉直接加热融化
C.温水中缓慢浸泡融化
D.琼脂恒温机加热融化
E.酒精灯加热融化