Complete
the
story
of
the
Bermuda
Triangle
with
the
past
perfect
simple
or
past
perfect
continuous
from
the
verbs
in
brackets
.
In
December
1945
,
five
military
planes
were
on
a
training
flight
after
they
had
____________________
(
take
off
)
from
an
airbase
in
Florida
in
the
USA
.
The
planes
____________________
(
fly
)
for
about
an
hour
and
they
____________________
(
fly
)
about
300
miles
when
without
warning
,
the
navigational
instruments
on
all
the
planes
,
which
____________________
(
work
)
perfectly
up
to
that
point
,
suddenly
stopped
working
.
Radio
contact
was
then
lost
.
None
of
the
planes
or
crew
was
ever
seen
again
.
The
official
explanation
is
that
before
they
vanished
,
the
planes
____________________
____________________
(
fly
)
into
an
area
of
unusual
magnetic
activity
.
It
is
believed
that
this
____________________
(
cause
)
their
compasses
and
other
equipment
to
malfunction
.
The
planes
were
flying
over
the
Atlantic
Ocean
near
Bermuda
and
the
story
of
the
Bermuda
Triangle
was
born
.
By
the
mid
-
1970s
,
sixteen
more
planes
____________________
(
mysteriously
/
disappear
)
in
the
same
area
.
And
it
appears
that
in
almost
all
cases
,
the
navigational
equipment
____________________
(
stop
)
working
just
before
the
planes
disappeared
.
