引弧的方法是将焊条末端与焊件表面接触，形成短路，然后迅速将焊条向上提起（）毫米的距离。

A．2～4

B．3～5

C．4～6

Accelerated analysis approaches emphasize the construction of （） to more rapidly identify business and user requirements for a new system. As an accelerated analysis technology,（） reads the program code and automatically generates the equivalent system model, and the code can be obtained from （） . All system analysis approaches require some form of （） which includes those techniques to be used to identify or extract system problems and solution requirements from user community. （） is a classical set of techniques used to collect information about system problems, opportunities, solution requirements, and priorities.

All system analysis approaches require some form of （）

A．requirement discovery

B．business process redesign

C．cause-and-effect analysis

D．total quality management