The movement of substances across the membrane can be either passive , occurring without the input of cellular energy , or active , requiring the cell to expend energy in moving it .
The movement of substances across the membrane can be either passive , occurring without the input of cellular energy , or active , requiring energy .
The movement of substances across the membrane can be either passive , occurring without the input of cellular energy , or active , requiring energy .
将句子改写得更简单: The movement of substances across the membrane can be either passive , occurring without the input of cellular energy , or active , requiring the cell to expend energy in moving it . 输出: