把下列句子改寫為“把”字句和“被”字句。   
1．白茫茫的大雪籠罩著山川、田野、村莊。
                                                                                                                                                         
                                                                                                                                                          
2．他送受傷的小鳥回家。
                                                                                                                                                      
                                                                                                                                                      
3．老班長吃了草根和魚骨頭。 
                                                                                                                                                      
                                                                                                                                                      
4．洪水吞沒了小伙子。