神经纤维受到刺激后会产生动作电位并沿神经纤维传导。下列叙述正_爱下问搜题

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问题选择题

神经纤维受到刺激后会产生动作电位并沿神经纤维传导。下列叙述正确的是[ ]

A．神经纤维中段受刺激产生的动作电位是单向传导的

B．发生动作电位时，膜电位是外正内负

C．膜对钠离子通透性的降低会导致动作电位变小

D．兴奋是以化学信号的形式沿神经纤维传导的

答案

答案：C

改错题

短文改错。
此题要求改正所给短文中的错误。对标有题号的每一行作出判断：
如有错误(每行只有一个错误)，则按下列情况改正：
此行多一个词：把多余的词用斜线(＼)划掉，在该行右边横线上写出该词，并也用斜线划掉。
此行缺一个词：在缺词处加一个漏字符号(∧)，在该行右边横线上写出该加的词。
此行错一个词：在错的词下划一横线，在该行右边横线上写出改正后的词。
注意：原行没有错的不要改。

I'm eighteen years old and I live in small village in
the Peak District, not far from Nottingham. I grow up
in t his village, so I know everyone here. That' s the
problem-the problem was that there' s nothing to do,
and nobody of my age to do it with ! At the moments I
travel into Nottingham every day to the shop as I work.
There's a bus at 7:30 in the morning or the last bus back
in the evening is at 5:30. From September, therefore,
I'm going to stay in Nottingham by my aunt and uncle
when my cousin joins in the Navy. I can use his room.
I'm really looking forward to living in Nottingham.

1______
2______
3______
4______
5______
6______
7______
8______
9______
10______

解答题

“下滑数”是一个数中右边数字比左边数字小的自然数（如：32，641，8531等），任取一个两位数，是“下滑数”的概率是 ______．