Curtain can be used for Blind. Blind is a type of Change. Change is related to Democratic. 
Pill is related to Vitamin. Vitamin is a type of Nutrient. Carbohydrate is a type of Nutrient. Carbohydrate is related to Fat. 
Curtain --UsedFor--> Blind --IsA--> Change <--RelatedTo--> Democratic 
Pill <--RelatedTo--> Vitamin --IsA--> Nutrient <--IsA-- Carbohydrate <--RelatedTo--> Fat 