请认真阅读下面对话，并根据各题所给字母的提示，在标有题号的右边横线上写出一个英语单词的完整、正确的形式，使对话通顺。

A:  Nowadays, doctors can do a great job transplanting organs such as the heart. As (76)m      science develops, I am sure that it will be several years (77)b_____ doctors are able to  transplant human brains. B:  I think you are right about that, but transplanting brains and transplanting memories are not (78)a_____ the same. A:  Why not? Our memories are in our brain, aren’t they? B: Yes. But it is not clear whether the memories will still be there if you transplant the brain. A:  Well, I (79)s_____ so. Why shouldn’t they? B: They may still be there. (80)B_____, in what other way could we then transplant memories? A:  Memories may be downloaded like a (81)c______. B: Oh, what you said is (82)b____ my imagination. But how would that (83)a_______ our society? A: Well, it would be great. We could (84)c_____ down all schools. People would not need to learn any more because (85)k__________could also be transplanted.