MCS-51单片机在正常运行程序时RST引脚是( )

A．高电平

B．低电平

C．脉冲输入

D．高阻态

Which function is NOT served by building a prototype

A．It takes the place of the final syste

B．It assists in gathering software requirements

C．It assists in estimating the cost of the projec

D．It is used as the foundation of the larger project