为了改善空气质量，确保身体健康，下面哪些做法是正确的（   ）

①经常在居室中喷杀虫剂，以杀死空气中的细菌    ②在居室周围多栽花草树木

③对新装修的房子经常打开窗户通气             ④晚间在居室摆放花卉

⑤焚烧秸杆                                ⑥教室经常保持空气流通．

                                                                                                   谢亭送别
                                                                                                       许浑
                                                                              劳歌一曲解行舟，红叶青山水急流。
                                                                              日暮酒醒人已远，满天风雨下西楼。
                                                                              【注】①劳歌：送别歌。