阅读下面的诗，完成下面题目。
                                                                                                            登岳阳楼
                                                                                                              杜甫
                                                                           昔闻洞庭水，今上岳阳楼。吴楚东南坼，乾坤日夜浮。
                                                                           亲朋无一字，老病有孤舟。戎马关山北，凭轩涕泗流。