Weak is the opposite of Healthy. you would Relax because Healthy. Relax is a type of Act. Anticipate is a type of Act. 
you are likely to find Shelf in/at/on Book. 
Weak <--Antonym--> Healthy <--MotivatedByGoal-- Relax --IsA--> Act <--IsA-- Anticipate 
Shelf --AtLocation--> Book 