To
fly
or
not
to
fly
?
For
years
,
environmentalist
1
)
have
been
warning
us
that
the
Earth
is
getting
warmer
.
And
most
experts
2
)
____________________
convinced
that
human
activity
is
to
blame
.
It
seems
that
3
)
____________________
more
we
pump
greenhouse
gases
into
the
atmosphere
,
the
more
the
Earth's
temperature
rises
.
Of
course
,
we
must
do
everything
we
4
)
____________________
to
save
our
planet
from
disaster
.
And
most
of
5
)
____________________
are
keen
to
get
involved
.
Some
of
us
walk
to
school
because
it
is
better
for
the
environment
6
)
____________________
going
by
car
.
We
try
to
remember
to
switch
7
)
____________________
lights
and
other
appliances
when
we're
not
using
them
.
So
far
,
so
good
.
None
of
this
hurts
so
much
.
But
now
a
well
-
known
campaigner
has
come
8
)
____________________
with
a
new
suggestion
.
Aeroplanes
generate
huge
amounts
of
greenhouse
gas
emissions
.
Maybe
,
the
campaigner
suggests
,
it's
9
)
____________________
we
gave
up
flying
for
pleausre
and
took
our
holidays
at
home
instead
.
But
are
people
prepared
to
change
their
lifestyles
in
such
10
)
____________________
big
way
?
Is
it
11
)
____________________
much
to
ask
?
