Express is related to Communication. Communication is related to Speech. Speech is related to Voice. 
Shark is a type of Insect. Insect is related to Nest. Nest is related to Mud. 
Express <--RelatedTo--> Communication <--RelatedTo--> Speech <--RelatedTo--> Voice 
Shark --IsA--> Insect <--RelatedTo--> Nest <--RelatedTo--> Mud 