Coffee
is
popular
around
the
world
.
Over
the
past
centuries
,
few
subjects
have
been
as
carefully
studied
as
coffee
.
It's
____________________
important
component
is
the
caffeine
and
it
has
lots
of
benefits
.
Coffee
has
been
well
-
known
____________________
the
beginning
of
the
14th
century
,
____________________
Sufi
Yemenis
started
using
coffee
to
stay
alert
during
special
activities
.
It
became
a
popular
medicine
____________________
Europeans
in
the
1600s
.
Caffeine
was
first
____________________
in
the
1800s
by
Ferdinand
Runge
,
a
doctor
that
found
out
some
effects
that
coffee
has
on
people
.
Some
people
say
____________________
coffee
isn't
good
,
but
doctors
say
you
____________________
believe
this
.
Thanks
to
caffeine
you
don't
get
hungry
.
Coffee
can
also
reduce
headaches
and
blood
problems
.
____________________
many
people
believe
coffee
is
bad
,
studies
show
it
is
good
for
your
heart
.
