按要求改写句子。
（1）What's this? It's a bus.（改为复数形式）
                                                            
（2）There is some milk in the glass.（改为一般疑问句）
                                                          
（3）Do it like that.（改为否定句）
                                                         
（4）He saw elephants yesterday.（改为一般疑问句）
                                                           
（5）She does her homework at 7:00.（改为否定句）