The
Earth
was
once
____________________
to
be
flat
.
____________________
,
observation
and
experimentation
have
led
us
to
our
present
knowledge
,
which
does
not
answer
all
our
questions
about
our
planet
,
____________________
.
Now
,
____________________
____________________
overpopupation
and
lack
of
resources
,
man
is
trying
to
explore
space
,
starting
with
planets
that
are
closer
to
Earth
,
before
we
____________________
try
to
inhabit
any
of
them
.
____________________
of
other
planets
,
____________________
____________________
further
technological
development
,
will
,
____________________
____________________
,
lead
us
to
further
exploration
of
the
planets
in
our
solar
system
,
and
____________________
those
which
lie
beyond
its
limits
.
