阅读下面一首唐诗，完成后面问题。
                                                                                                       月 夜
                                                                                                      刘方平 
                                                                                    更深月色半人家，北斗阑干南斗斜。
                                                                                    今夜偏知春气暖，虫声新透绿窗纱。