Read this excerpt from mayor seth low's speech at the opening of the brooklyn bridge.

gentlemen of the trustees—with profound satisfaction, on behalf of the city of brooklyn, i accept the completed bridge. fourteen times the earth has made its great march through the heavens since the work began. the vicissitudes of fourteen years have tried the courage and the faith of engineers and of people.

low's style is

formal; he uses complex words that are appropriate for the ceremony, and his purpose is to inform his audience.
formal; he uses academic language because his purpose is to teach the scientific facts behind the building of the bridge.
informal; he uses casual language because his purpose is to persuade the audience.
informal; he uses humorous language, and his purpose is to entertain the audience.