Sister: leaves fans and lights in her room when she comes out
me: see,you must not leave those like that
me : as wasting electricity is not good
sister:then what shall i do
me : you can just put them off when your out of your room
sister:if i wont what is the problem
me :if you wont then we have to pay a huge electric bill ,are you ready to pay.
sister : ok ! i will not waste the electricity and switch off once i am out of my room.
me :that's good.