在某一温度下，两个电路元件A和B中的电流与其两端电压的关系如图所示。则由图可知，元件A的电阻为____________Ω；元件B的电阻为__________Ω将A和B并联后接在电压为2.5V的电源两端，则通过A和B的总电流是_____________A。

I can never forget the days________we worked together and the days________we spent together.[ ]

A．on which；when  

B．which；when

C．what；that  

D．when；which