Question: The great grandson of the Liberal prime minister William Ewart Gladstone, and brother of Sir William Gladstone, competed in what event between Oxford University and Cambridge University on the River Thames?
Sentence (from "The Boat Race"): The Boat Race is an annual rowing race between the Oxford University Boat Club and the Cambridge University Boat Club, rowed between men's open-weight eights on the River Thames in London, England.
Relevant evidence: Yes