To define variance thresholds at designated time points over the duration of a project, you will use （）.

A．units of measure

B．precision level

C．organizational procedure links

D．control thresholds

市（州）局计算机房应安装感温、感烟报警器，并采用自动气体灭火系统。县（市）分局计算机房应安装感温、感烟报警器，并配备气体灭火器。