How about an AI teacher?

An interesting question in contemporary philosophy asks, if a machine can function *precisely* like a human, is there a relevant difference between the machine and the human? The answer seems to be, "no." So if it were possible to have an AI program function *precisely* like a school teacher, I see no problem in using such a machine. The problem is in the making: (1) what does a school teacher do? (2) how can a machine do it? It's easy to see phone operators replaced by machines.