题目

研究者为了研究神经元之间兴奋的传递过程，选用枪乌贼的神经组织进行实验，处理及结果见下表。 实验 组号处理微电极刺激突触前神经元测得动作电位（mV）室温，0.5ms后测得突触后神经元动作电位（mV） I未加河豚毒素（对照）7575 II浸润在河豚毒素中5min后6565 III10min后5025 IV15min后400 （1）第I组处理说明枪乌贼神经元兴奋时，膜外比膜内电位__________75mV。室温下，微电极刺激突触前神经元测得动作电位0.5ms后，才能测到突触后神经元的动作电位，Born in England in 1944, Ian Wilmut 【1】(know)as the leader of the research group that first cloned a female lamb 【2】(call)Dolly in 1996. Dolly became famous and pictures of her appeared on the 【3】(cover)of magazines all over the world. The 【4】(possible)of reproduction without a male and female being involved also made her the focus of a moral debate. For scientists, however, the cloning of dolly using the DNA of an adult cell was a breakthrough 【5】showed the cloning of special animals was possible.However, 【6】Wilmut thinks unlikely is human cloning. He says 【7】(undertake)the procedure with humans would require 29 surrogate(替代的)mothers and 300 eggs. Of those 29,28 would be bound 【8】(experience)failure and suffer physically and emotionally. He says he is also concerned about the psychological and 【9】(society)consequences a cloned might have to go through. For these reasons, he is not 【10】favor of it.