—What's the noise ? It sounds as if it comes from upstairs．

—_________．It must be the window-cleaner working , next door．

A．I'm not sure                                                    B．I hope not

C．I'd rather not                                          D．I don't think so

–What’s the noise ? It sounds as if it comes from upstairs.  
--______. It must be the window-cleaner working , next door.         

What’s the noise ? It sounds as if it comes from upstairs.  
--______. It must be the window-cleaner working , next door.         

. –What’s the noise ? It sounds as if it comes from upstairs.  
--______ .It must be the window-cleaner working , next door.