Circumstance is related to Happen. Happen is related to Go. Go is related to Death. Death is part of War. 
Length is related to Century. Century is related to Lot. Lot is related to Considerable. Considerable is similar to Significant. 
Circumstance <--RelatedTo--> Happen <--RelatedTo--> Go <--RelatedTo--> Death --PartOf--> War 
Length <--RelatedTo--> Century <--RelatedTo--> Lot <--RelatedTo--> Considerable <--SimilarTo--> Significant 