TASK DEFINITION: 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 consistency, answers should be in all lower cased letters.
PROBLEM: Category: ON A SWISS ARMY KNIFE 
Clue: There are 2 of these, one for wood & one for metal

SOLUTION: a saw

PROBLEM: Category: MOUNTAINS 
Clue: Yosemite National Park is located in this California mountain range

SOLUTION: sierra nevadas

PROBLEM: Category: TALL STRUCTURES 
Clue: The service elevators in this St. Louis edifice rise at an angle of 78 degrees

SOLUTION:
the gateway arch