阅读下面一首诗，完成后面小题。
                                                                                                  次北固山下
                                                                                                      王 湾
                                                                                       客路青山外，行舟绿水前。
                                                                                       潮平两岸阔，风正一帆悬。
                                                                                       海日生残夜，江春入旧年。
                                                                                       乡书何处达？归雁洛阳边。