Task: Question Generation
Input (English): Context : Before its departure to California in 1922, The Blue Boy was briefly put on display at the National Gallery where it was seen by 90,000 people; the Gallery's director Charles Holmes was moved to scrawl farewell words on the back of the painting: ``Au Revoir, C.H.''. 
Subject : The Blue Boy 
Relation : collection
Output (English): What is the name of the place where The Blue Boy can be found?