I sent for a technician ______ John isn’t familiar ______ the computer software they use?

A．in case, with

B．in case, to

C．as if, for

D．so that, in

污水流量和水质变化的观测周期越长，调节池设计计算结果的准确性与可靠性（）。

A．越高

B．越低

C．无法比较

D．零