Choose
from
the
following
sentences
to
fill
the
spaces
in
the
text
.
There
is
one
extra
.
A
.
Using
a
microwave
for
cooking
a
large
food
mass
is
difficult
due
to
limited
penetration
of
microwaves
.
B
.
This
can
be
overcome
by
leaving
the
food
to
stand
for
a
few
minutes
when
cooking
is
completed
.
C
.
It
is
advised
that
the
water
should
be
poured
slowly
into
another
container
that
already
contains
the
powder
.
D
.
In
this
way
,
buying
a
microwave
oven
with
a
turntable
ensure
the
food
is
cooked
throughout
.
E
.
Conversely
the
microwaves
do
not
heat
glass
,
ceramic
and
plastic
containers
.
F
.
If
the
microwaves
are
not
absorbed
inside
the
oven
,
the
oven
can
be
damaged
by
electrical
arcs
and
overheating
of
the
microwave
source
.
G
.
When
water
in
that
state
is
disturbed
,
it
can
suddenly
and
unexpectedly
boil
violently
.
Microwaving
is
a
method
of
cooking
where
food
is
bombarded
by
microwaves
,
usually
within
an
appliance
called
a
microwave
oven
which
excite
the
water
,
fat
and
sugar
molecules
,
thereby
heating
(
cooking
)
both
the
outside
and
center
of
the
food
at
the
same
time
.
[
1
]
[
A
common
myth
is
that
a
microwave
oven
cooks
from
the
center
of
the
food
outward
.
This
appears
to
happen
because
heat
generated
at
the
surface
escapes
more
readily
from
the
surface
of
the
food
into
the
surrounding
air
.
]
One
advantage
of
microwaving
is
that
small
amounts
of
food
can
be
heated
very
quickly
,
making
it
useful
for
reheating
leftovers
.
The
disadvantage
is
that
food
which
is
microwaved
does
not
undergo
some
of
the
chemical
reactions
,
such
as
browning
,
which
makes
the
food
visually
attractive
.
Primitive
microwave
ovens
often
do
not
cook
evenly
,
leading
to
a
concern
that
bacteria
easily
killed
by
more
traditional
cooking
methods
may
survive
the
quick
cooking
time
in
"
cold
spots
"
,
though
the
food
item
as
a
whole
is
cooked
to
a
safe
average
temperature
.
[
2
]
Some
high
-
end
microwave
ovens
are
combined
with
a
convection
oven
which
basically
cook
the
food
using
microwave
and
hot
air
simultaneously
to
achieve
both
the
fast
cooking
time
and
browning
effect
.
[
3
]
.
However
microwave
ovens
are
used
in
some
fast
food
chains
and
special
microwave
bags
are
available
for
cooking
fowl
or
large
joints
of
meat
.
Professional
chefs
generally
recommend
using
microwaves
for
a
limited
set
of
tasks
,
including
:
melting
fats
(
such
as
butter
)
and
chocolate
,
cooking
grains
like
oatmeal
and
grits
,
cooking
rice
,
thawing
frozen
meats
and
vegetables
before
cooking
by
other
methods
and
quickly
reheating
already
-
cooked
foods
.
Using
a
microwave
to
boil
water
is
potentially
dangerous
,
due
to
superheating
.
In
a
microwave
,
water
can
be
raised
quickly
to
a
temperature
above
the
boiling
point
before
major
bubbles
form
,
especially
if
it
is
purified
and
in
a
very
clean
glass
vessel
.
[
4
]
.
This
effect
is
rare
,
even
for
scientists
who
try
to
deliberately
recreate
it
,
and
any
seed
whatsoever
for
boiling
is
likely
to
prevent
the
problem
.
Boiling
water
with
,
for
instance
,
a
teabag
already
in
it
will
prevent
any
dangers
by
providing
a
seed
,
as
will
using
a
mug
that
is
not
perfectly
clean
.
The
risk
greatly
increases
when
water
has
already
been
boiled
once
in
the
same
container
.
This
situation
can
occur
if
the
user
of
the
oven
boiled
the
water
once
,
forgot
about
it
,
then
came
back
later
to
boil
it
again
.
The
first
time
the
water
boils
,
the
seed
bubbles
(
microscopic
bubbles
of
air
around
which
larger
steam
bubbles
grow
)
are
used
up
and
largely
eliminated
from
the
water
as
it
cools
down
.
When
the
water
is
heated
again
,
the
lack
of
seed
bubbles
causes
superheating
,
and
a
risk
of
a
steam
explosion
when
the
water's
surface
is
disturbed
.
Placing
something
in
the
water
before
heating
can
mostly
alleviate
this
risk
.
If
you
are
planning
to
mix
something
with
the
water
,
say
tea
or
hot
chocolate
,
adding
it
before
heating
will
insure
that
the
water
boils
.
Otherwise
,
placing
a
wood
object
,
for
instance
a
chopstick
,
in
the
water
before
heating
will
also
work
.
Care
should
be
taken
when
removing
heated
water
from
a
microwave
.
Make
sure
that
the
hands
are
protected
from
possible
liquid
boil
-
over
,
place
the
container
on
a
level
,
heat
-
proof
surface
and
stir
liquid
with
a
warm
spoon
.
Also
,
never
add
powdered
substances
(
such
as
instant
coffee
or
cocoa
mix
)
to
the
container
taken
from
the
microwave
,
due
to
the
addition
of
all
those
seed
bubbles
and
the
potential
for
violent
,
spontaneous
boiling
.
[
5
]
Metal
objects
,
such
as
metal
utensils
,
in
a
microwave
oven
can
lead
to
dangerous
situations
.
Metals
do
not
absorb
microwaves
effectively
.
Instead
,
metals
reflect
microwaves
,
thereby
preventing
the
latter
from
reaching
the
food
.
[
6
]
.
Thin
metal
layers
,
such
as
metal
foil
and
mugs
with
metal
trim
can
melt
or
burn
due
to
the
strong
electrical
currents
that
are
generated
in
metal
objects
.
However
,
small
solid
metal
objects
,
such
as
spoons
,
in
combination
with
a
large
amount
of
absorbing
food
or
liquid
,
normally
do
not
lead
to
problems
.
Completa las frases con la forma correcta del verbo que se encuentra entre paréntesis.
