--- Let’s go to Canada for a holiday.

--- Sorry, we won’t go there. All of us except him _______ to Canada.

A．have gone

B．has gone

C．have been

D．has been

细胞膜通过本身的某种耗能过程，将某物质的分子或离子由膜的低浓度一侧移向高浓度一侧的过程，称为：（）

A．单纯扩散

B．易化扩散

C．主动转运

D．出胞与入胞式物质转运