1
)
Sound
is
said
to
be
____________________
when
sound
waves
spread
in
all
direction
.
2
)
Transmission
of
sound
is
fastest
in
____________________
medium
.
3
)
The
sound
which
is
disagreeable
to
the
ears
is
called
____________________
.
4
)
Propagation
of
sound
does
not
occur
through
a
____________________
.
