name the military unit whose garrison is virginia and command structure is office of the administrative assistant to the secretary of the army ?
SELECT DISTINCT var_uri where brack_open var_uri dbo_garrison dbr_Virginia sep_dot var_uri dbo_commandStructure dbr_Office_of_the_Administrative_Assistant_to_the_Secretary_of_the_Army sep_dot var_uri a dbo_MilitaryUnit brack_close