阅读下面古诗，回答小题。

                                                                                                                             东栏梨花

                                                                                                                               苏轼

                                                                                                     梨花淡白柳深青，柳絮飞时花满城。

                                                                                                    惆怅东栏一株雪，人生看得几清明！