Okay is related to Occasion. Occasion is a type of Time. Time is related to Century. Century is related to Decade. 
Cover is part of Notebook. Cover is related to Garbage. Garbage is a type of Refuse. Refuse can be used for Speak. 
Okay <--RelatedTo--> Occasion --IsA--> Time <--RelatedTo--> Century <--RelatedTo--> Decade 
Notebook <--PartOf-- Cover <--RelatedTo--> Garbage --IsA--> Refuse --UsedFor--> Speak 