demonstrate

verb

1. give an exhibition of to an interested audience"She shows her dogs frequently"
2. establish the validity of something, as by an example, explanation or experiment"The experiment demonstrated the instability of the compound"
3. provide evidence for; stand as proof of; show by one's behavior, attitude, or external attributes"His high fever attested to his illness"
4. march in protest; take part in a demonstration"Thousands demonstrated against globalization during the meeting of the most powerful economic nations in Seattle"