Please list the departments that David Bradley used to belong to.
SELECT T2.DepartmentID FROM Person AS T1 INNER JOIN EmployeeDepartmentHistory AS T2 ON T1.BusinessEntityID = T2.BusinessEntityID INNER JOIN Department AS T3 ON T2.DepartmentID = T3.DepartmentID WHERE T1.FirstName = 'David' AND T1.LastName = 'Bradley'