(I) Inject the vaccine into the experimental rabbits, and after a period of time, inject the experimental rabbits with influenza A virus, and find that the rabbits injected with the vaccine will not be infected with influenza A virus. Experimental conclusion: The vaccine has made the experimental rabbits immune. The experimental process is not enough to strictly demonstrate the conclusion of N because of the lack of control group experiments.

(2) Design control experiment: ① Material number: A number of healthy experimental rabbits with similar growth conditions were randomly divided into group A and group B. 。

② Different treatments were given: group A was vaccinated, group B was vaccinated with the same amount of normal saline, and after a period of time, the same amount of influenza A, W, N and I virus were injected respectively.

③ Observation of experimental results: Under the same and suitable conditions, after observing the oral period, the incidence of rabbits in group A and group B was counted.

Predictive experimental results: The incidence of influenza A, W, N and I in rabbits in group A is much lower than that in rabbits in group B because the rabbits in group A are vaccinated and produce memory cells.

So the answer is:

(I) A W I N I influenza virus? Lack of control group experiment

(2)① Several healthy experimental rabbits with similar growth conditions.

② Inject the same amount of influenza A W I N I virus.

③ The incidence of rabbits in group A and group B was lower than that in group B.