（1 ） is a method of constructing a project schedule network diagram that uses boxes or rectangles,referred to as nodes,to represent activites and connects them with arrows that asow the dependencies.This method includes following types of dependcies orprecedence relationships: （2 ）the initiation of the successor activity, depends upon the completion of the predecessor activity.（3）the initiation of the successor activity, depends upon the initiation of the predecessor activity.
（1）A．PDM                B．CPM               C．PERT             D．AOA
（2）A．F-S                  B．F-F                C．S-F               D．S-S
（3）A．F-S                  B．F-F                C．S-F               D．S-S