阅读下面的诗歌，完成练习。     

                                                                    乡愁   

                                                           小时候   

                                                           乡愁是一枚小小的邮票   

                                                           我在这头   

                                                           母亲在那头   

                                                           长大后   

                                                           乡愁是一张窄窄的船票   

                                                           我在这头   

                                                           新娘在那头   

                                                           后来呵   

                                                           乡愁是一方矮矮的坟墓   

                                                           我在外头   

                                                           母亲在里头   

                                                           而现在   

                                                           乡愁是一湾浅浅的海峡   

                                                          我在这头  

                                                          大陆在那头

1．这首诗是按照                       顺序写的， 表达了诗人                          的思想感情。   

2．诗中，“一湾浅浅的海峡”是指                               海峡。   

3．诗人为什么把乡愁比喻成“邮票”、“船票”？

4．诗人又为什么把乡愁比喻成“坟墓”、“海峡”？

5．全诗你最喜欢的是                               这一句，因为                                             。

治安警告由公安机关裁决，不必填写裁决书。