Classical is a synonym of Classic. Classic is related to Bear. Bear is a synonym of Absorb. 
Transportation is related to Tunnel. Tunnel is related to Cave. Cave is a type of Explore. 
Classical <--Synonym--> Classic <--RelatedTo--> Bear <--Synonym--> Absorb 
Transportation <--RelatedTo--> Tunnel <--RelatedTo--> Cave --IsA--> Explore 