有关动作电位的说法中，不当的是（） A.动作电位或峰电位的产生

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问题单项选择题 A1/A2型题

有关动作电位的说法中，不当的是（）

A.动作电位或峰电位的产生是细胞兴奋的标志

B.只要刺激达到足够的强度，再增加刺激强度能使动作电位的幅度增大

C.动作电位不是只出现在受刺激的局部

D.动作电位传播的范围和距离不因初刺激的强弱而有所不同，直至整个细胞的膜都依次产生同样的动作电位

E.动作电位是先出现膜的快速去极化再出现复极化

答案

参考答案：D

解析：：动作电位产生的特点是，只要刺激达到足够的强度，再增加刺激强度并不能使动作电位的幅度增大，始终保持某种固有的大小和波形。

完形填空

In a national spelling contest in America，an 11-year-old girl was asked to spell a certain word. But with her 36 voice the judges were not sure whether she spelled the word with the letter A or E. They talked it over and 37 decided to simply ask her what she had said. By now, the girl knew she had 38 the word. But instead of lying，she told the truth that she had said the 39 letter—so she lost the contest.
As the girl walked off the 40 ，the entire audience stood to their feet clapping to applaud her
41 . Later，dozens of newspaper reporters wrote about this 11-year-old girl’s honesty，even when it 42 her the contest. But the fact is that she 43 the biggest contest that day: the contest of her 44 .
Probably the biggest test of our character and honesty is that we would do if we knew we would never get 45 .This young girl could easily have 46 and nobody would have known it but herself. But that’s just it: She would know she did wrong. It’s been said, “If you 47 , you make yourself cheap.” This young girl was strong and smart enough to prize her own 48 and character more than the prize from a spelling 49 . Her respect for herself was more important than any 50 others might give her for winning a contest. She knew she would have to live with herself and the 51 she made in that moment will have long-lasting influence.
It’s so true that the choices you make today 52 what you are tomorrow. Our children will 53 our behaviour much more than our advice. So if we want them to 54 to be honest，we must show them the way by being honest ourselves. Remember，our kids are 55 what we do and how we live even when we don’t think they see or know.

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选择题

邓 * * 说：“证券、股市，这些东西究竟好不好，有没有危险，是不是资本主义独有的东西，社会主义能不能用？允许看，但要坚决地试。看对了，搞一两年对了，放开；错了，纠正，关了就是了。”这段话主要反映的是[ ]

A．经济建设既要防“左”又要反“右”

B．经济体制改革重心从农村转向城市

C．设立沿海经济特区有必要进行试验

D．市场经济并不是资本主义所独有的

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