问题
                    
The old man told us _______ and ________.
                            A:to do what , to do how
B:what to do it, how to do it
C:what to do, how to do it
D:what to do , how to do
                        
                        B:what to do it, how to do it
C:what to do, how to do it
D:what to do , how to do
正确答案是: