Communications technology factors that can affect the project include all of the following EXCEPT______．

A．the length of the project

B．the availability of technology

C．executive requirements

D．the urgency of the need for information

目前船舶15ppm级油水分离器一般是（）。

A．单级分离，采用重力分离法

B．二或三级分离，先吸附分离，后重力分离

C．二或三级分离，先过滤分离，后离心、吸附分离

D．二或三级分离，先重力分离，后过滤、吸附分离