You are working on a software development project. On this project, a number of tests must be performed, including some that must be performed multiple time. The project includes activities whose sequence is conditional based on the outcomes of prior activities. For example, if an error is discovered through inspection, the project’s design may have to be modified, creating the need for additional testing. The network technique best able to handle these situations is ______ .

A．PDM network

B．PERT chart

C．GERT network

D．ADM network

在学习达到刚好记忆水平以后再进行的学习称之为______。