demonstrate

Provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes.

“This decision demonstrates his sense of fairness”

Give an exhibition of to an interested audience.

Establish the validity of something, as by an example, explanation or experiment.

“The experiment demonstrated the instability of the compound”

March in protest; take part in a demonstration.

“Thousands demonstrated against globalization during the meeting of the most powerful economic nations in Seattle”