A:形成局部电流
B:细胞膜两侧电位差保持不变
C:抑制细胞兴奋
D:使细胞膜内电位由正变负
— should we clean the library?
—Twice a week.
下列加线的成语使用正确的一项是 ( )
— Simon, when are we going to have a class meeting this week? — Sorry. Ask our monitor, please. He know.
希波战争发生时,我国正处于哪个历史时期( )