FATHER- Son, Isn't your History exam tomorrow?
SON- Yes, is it there.
FATHER- Then why are you watching TV?
SON- I have completed learning my syllabus, dad.
FATHER- But have you done the revision?
SON- No, dad, revision is left.
FATHER- Revision is must after completing the exam.
SON- Sure dad, i will do it after 15 minutes break.
FATHER- Good! all the best for your exam.
SON-Thankyou and Goodnight.