name the office holder whose predecessor is george curzon and successor is william cove ?
SELECT DISTINCT var_uri where brack_open var_uri dbp_predecessor dbr_George_Curzon,_1st_Marquess_Curzon_of_Kedleston sep_dot var_uri dbp_successor dbr_William_Cove sep_dot var_uri a dbo_OfficeHolder brack_close