补写下列名句。  

1．书犹药也，                               。   

2．                                    ，游子久不至。    

3．                                    ，人在天涯鬓已斑。    

4．滴水能把石穿透，                                   。    

5．孝在于质实，                                        。    

6．                                        ，梅花香自苦寒来。