蜂针疗法是利用工蜂蜂毒防治疾病的一种方法，蜂毒肽是蜂毒的主要成分及主要活性物质．请回答：

（1）蜂毒肽基本组成单位的结构通式是　____ ．

（2）研究表明：蜂毒肽作用于突触后膜上的____ ，阻滞乙酰胆碱与其结合，使乙酰胆碱不能发挥作用，故蜂毒肽对神经系统具有抑制作用．

（3）科研人员为研究蜂毒肽对人肝癌细胞增殖的影响，进行了以下实验，结果如下表．

蜂毒肽对肝癌细胞的增殖抑制率

注：细胞增殖抑制率（%）=（1﹣实验组活细胞数/对照组活细胞数）×100%

请补充实验步骤并回答：

①取7个相同培养瓶并编号，分别加入等量的____ 完全培养液并接种．

②各培养瓶中分别加入____ μg/mL蜂毒肽溶液，其中1号为对照组．

③培养72小时后，检测并计算肝癌细胞增殖抑制率．

④实验结果表明：____ ．

   Once there was an old man in a town. He always forgot a lot of things. So his wife always had to say to him, "Don’t forget this ! "
One day he went on a long trip alone. Before he left home, his wife said, "Now you have all these things. They are what you need for your trip. Take care of your things during the trip." He went to the station, bought a ticket and got on the train with it.
   About half an hour later, the conductor began to see the tickets. He came to the old man and said, "Will you please show me your ticket?" The old man looked for his ticket in all his pockets, but he could not find it. He was very worried. “I can’t find my ticket. I really bought a ticket before I got on the train." said the old man.
   “I believe you bought a ticket. All right, you don’t have to buy another one," said the conductor kindly. "But how can I know where I’m going? ---I can’t remember my station!" the old man said sadly.