----Must I do well in all the subjects, Mum?
----Sure, baby! As an old saying goes, knowledge is _________.

--Must I do it now?

--No, you _____.

A. won’t              B. needn’t               C. can’t          D. don’t

----Must I do well in all the subjects, Mum?

----Sure, baby! As an old saying goes, knowledge is _________.

—Must I do well in all the subjects，Mum?

—Sure，baby！As an old saying goes，knowledge is________.

A．command                             B．effort 

C．power                                  D．energy

—Must I do it now?

—No,you _____.

A.won’t

B.needn’t

C.can’t

D.don’t