Question

Why acid and base don't show their action in dry state?

Answer 1

Acids and bases are kind of dormant( asleep) in dry state since no change of position of ions can take place in dry state. Only when they are in a molten( liquid) form can ions freely move.
Please try to understand this not as a theoretical( bookish) but as a practical concept.
:D 

Answer 2

Acids and bases are kind of inactive in their dry state and hence no change of position of ions can take place in dry state.When they are liquid, only then the ions can freely move.

Hope this will help you .