何谓主动转运?
参考答案:
细胞膜通过本身的某种耗能过程,将某种物质的分子或离子由膜的低浓度或低电位一侧移向高浓度或高电位一侧的过程(逆电-化学梯度转运),称为主动转运。
Helen was so excited at the news that she could say a word.
A.ever
B.almost
C.hardly
D.always
下列哪种上睑下垂患者首先应考虑手术治疗()
A.先天性上睑下垂
B.麻痹性上睑下垂
C.重症肌无力性上睑下垂
D.获得性上睑下垂
E.神经系统疾病所致的上睑下垂