You will be given a trivia clue, and the category it belongs to. You should answer with the best answer that belongs in the category and is described by the clue. For simplicity, answers should be in all lower cased letters.

Category: FISH, BIRD, OR MAMMAL 
Clue: The colobus
mammal

Category: HISTORIC EUROPEAN LEADERS 
Clue: On June 15, 1961 Walter Ulbricht assured journalists that "No one intends to build a wall" dividing this city
berlin

Category: PREPOSITIONAL PHRASES 
Clue: In a 19th century poem, it precedes "...and through the wood, to Grandfather's house we go"

over the river

