Bag is related to Hold. Hold is related to Tension. Tension is a type of Stress. Stress can be Epidemic. 
Stretch is related to String. String is a type of Rope. Rope is related to Wire. 
Bag <--RelatedTo--> Hold <--RelatedTo--> Tension --IsA--> Stress --HasProperty--> Epidemic 
Stretch <--RelatedTo--> String --IsA--> Rope <--RelatedTo--> Wire 