1.   Energy efficiency can play a huge role in reducing pollution.

2.   Great strides have been made in reducing air pollution in US cities.

3.   Italian cities have imposed alternate-day driving rules in an effort to reduce pollution.

4.   New measures are needed to reduce pollution from cars.

5.   The change reflects the continuing failure by state and local governments to reduce pollution enough to meet federal health standards.

6.   The countries agreed to adopt measures to reduce pollution.

7.   The government has set up a working party to formulate proposals for reducing environmental pollution.

8.   The obvious way of reducing pollution is to use cars less.

9.   The remaining gases pass through a catalytic converter to further reduce pollution.