Its pretty simple... If the girl loves him really then she
could teach the alphabets and could make him touch
sensitive to the letters. in that way she could easily
propose her love.

although he might be blind ,deaf & dump but he can feel the
things that surrounds him, definetly he requried training
it is a tedious job but not impossible.

As he can smell, so she has put to good fragrances and
observe which one attract him most. Once he starts
responding to one he likes most, it means he has accepted
her (proposal).
She can start with Rose(symbol of love)

Consider sinc(x):where sinc(x)=sin (xpi)/xpi.
and sinc(x) have max value i.e. unity at x=0 .now if
x=0.then pix =0 and sin (pix)=0 at x=0. then above
expression sin (xpi)/xpi.should be of 0/0 form i.e.
in-determined form. then how sinc(x) is one at x=0.
pi is constant.