should be changed into another form fBd=A0(∑I+∑Im in which the molecular current (or the polarizing current极化电流) is added It is not convenient(方便) to use the above formula since the polarizing current is unknown B -00-0 ----e (8-(0should be changed into another form B d ( I I )  =  c + m  0     in which the molecular current (or the polarizing current 极化电流) is added. It is not convenient（方便） to use the above formula since the polarizing current is unknown. B