In level 2 when you are in the zoo if you have trouble getting past the gestapo if you look around you will see a man in a blue uniform (he is the zoo guard).
Go over to the garrison that is outside the zoo in a soldiers uniform and kill all the soldiers that are there and then hide them when the zoo guard comes knock him out and take his uniform.
kill him with the cyanide put on his uniform and the soldiers will not notice you.
P.S. You can also go in lions pen and not get eaten but don't shoot the lions or the soldiers will kill the general but you can inject them with the cyanide.
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