Lens is related to Eye. Eye can be used for Reading. Reading requires Book. Book is related to Essay. 
Expertise is a type of Ability. Ability is related to Speech. Speech is related to Long. Long is related to Course. 
Lens <--RelatedTo--> Eye --UsedFor--> Reading --HasPrerequisite--> Book <--RelatedTo--> Essay 
Expertise --IsA--> Ability <--RelatedTo--> Speech <--RelatedTo--> Long <--RelatedTo--> Course 