排排队按一定的顺序把下面各组词语重新排列。   
1．天    月    旬    星期
                                                                                                     
2．古代  现代  当代    近代 
                                                                                                    
3．哺乳动物    鲸    动物    蓝鲸 
                                                                                                    
4．写提纲   修改   草稿   构思