A project life cycle is a collection of generally sequential project（）whose name and number are determined by the control needs of the organization or organizations involved in the project. The life cycle provides the basic（）for managing the project, regardless of the specific work involved.

The life cycle provides the basic（）for managing the project, regardless of the specific work involved.

A．plan

B．fraction

C．main

D．framework

双自动闭塞区间，自前一列车通过车站之时起，至追踪运行的次一列车通过该站时止最小间距时间称为（）。

A.I追

B.I通

C.I发

D.I到