Do is the opposite of Observe. Observe is derived from Observer. Observer is a type of Expert. Investigator is a type of Expert. 
Practice is related to Hard. Hard is related to Tree. Tree is related to Toy. 
Do <--Antonym--> Observe --DerivedFrom--> Observer --IsA--> Expert <--IsA-- Investigator 
Practice <--RelatedTo--> Hard <--RelatedTo--> Tree <--RelatedTo--> Toy 