Mexico
____________________
,
the
capital
of
____________________
,
has
some
of
the
worst
____________________
pollution
of
any
major
city
on
Earth
.
The
____________________
comes
from
the
city's
low
____________________
and
the
energy
and
transportation
requirements
of
its
nearly
9
____________________
residents
.
Between
the
____________________
and
____________________
power
plant
emissions
and
vehicle
exhaust
,
Mexico
City's
air
quality
is
extremely
____________________
.
Air
____________________
flags
are
flown
daily
to
designate
the
smog
levels
,
particularly
in
the
dry
winter
months
.
In
an
effort
to
____________________
its
air
pollution
problem
,
Mexico
City
____________________
the
number
of
days
its
citizens
are
____________________
to
operate
their
personal
motor
vehicles
.
Mass
transit
systems
,
such
as
the
city's
____________________
and
train
networks
,
are
encouraged
as
an
alternative
means
of
transportation
*
*
*
Adapted
from
the
Georgia
Deparment
of
Education
6th
Grade
Social
Studies
Teacher
Notes
for
the
Georgia
Standards
of
Excellence
in
Social
Studie
s