--Who has broken the window in my room?

    --Who else _________ it but your naughty son!

    A. could do                          B. could have done

    C. should have done                   D. must have done

—Who has broken the window in my room?

   —Who else      it but your naughty son!

         A．could do     B．could have done         C．might do                       D．must have done

–Who has broken the window in my room?

   --Who else ___ it but your naughty son!

A. could do           B. could have done C. might do    D. must have done

–Who has broken the window in my room?

   --Who else ___ it but your naughty son!

A. could do           B. could have done C. might do    D. must have done

 --Who has broken the window in my room?

    --Who else _________ it but your naughty son!

    A. could do                          B. could have done

    C. should have done                   D. must have done