Utilize is a type of Change. Warm is a type of Change. Warm is related to Tea. Tea is related to Cake. 
Rack is related to Shelf. you are likely to find Speaker in/at/on Shelf. Speaker is a type of Product. 
Utilize --IsA--> Change <--IsA-- Warm <--RelatedTo--> Tea <--RelatedTo--> Cake 
Rack <--RelatedTo--> Shelf <--AtLocation-- Speaker --IsA--> Product 