第7题: [单项选择]用河豚毒处理神经轴突后,可引起 A. 静息电位减小,动作电位幅度和锋电位增大 B. 静息电位和动作电位幅度增大,锋电位减小 C. 静息电位不变,动作电位幅度和锋电位增大 D. 静息电位不变,动作电位幅度和锋电位减小 参考答案:D 答案解析:河豚毒是Na+通道的特异性抑制剂,用河豚毒处理神经轴突后,Na+内流受到抑制。由于静息电位总是接近于K+平衡电位,且比K+<
第9题: [单项选择]How long does it take him to finish writing a book A. In only three years. B. More than three years. C. Three years. D. Less than three years. 参考答案:B 答案解析:[听力原文]
Three years is not enough for him to finish writing a book.
Question: How long does it take