you are likely to find Teenager in/at/on Roof. Teenager is a synonym of Adolescent. 
Level is related to Certain. Certain is related to Particular. Particular is related to Real. Real is the opposite of Ghost. 
Roof <--AtLocation-- Teenager <--Synonym--> Adolescent 
Level <--RelatedTo--> Certain <--RelatedTo--> Particular <--RelatedTo--> Real <--Antonym--> Ghost 