Question: HMS "Royal Oak" was one of how many, "Revenge"-class battleships, built for the Royal Navy during the First World War?
Sentence (from "Revenge-class battleship"): The Revenge"-class battleships (listed as Royal Sovereign" class in several editions of "Jane's Fighting Ships", as with the 1919 and 1931 editions, and sometimes also known as the "R" class) were five battleships of the Royal Navy, ordered as the First World War loomed, and launched in 1914–16.
Relevant evidence: Yes