name the common serving line of khao chum thong junction railway station and alor setar railway station ?
SELECT DISTINCT var_uri where brack_open dbr_Khao_Chum_Thong_Junction_Railway_Station dbo_servingRailwayLine var_uri sep_dot dbr_Alor_Setar_railway_station dbo_servingRailwayLine var_uri brack_close