11.   In automobiles, they help reduce harmful emissions.

12.   In fact, Ethyl says, MMT will cut harmful emissions of nitrogen oxides and carbon monoxide and will save large amounts of crude oil in the production process.

13.   In the United States, automobile manufacturers build bigger, more gas-guzzling cars, and harmful emissions rise and public transportation atrophies.

14.   New diesel engines that burn a fuel that is lower in sulfur would cut nitrogen oxide and other harmful emissions.

15.   The cleaner cars will use new technologies to decrease harmful emissions.

16.   These initiatives might lead to further changes in the Clean Air Act that regulates potentially harmful emissions in the United States.

17.   An active campaigner against air pollution, he has proposed regulations that would require trucking companies to cut harmful emissions from diesel engines.

18.   Efforts of industrialized nations to cut harmful emissions have often been frustrated by objections from developing countries, which cannot as easily afford to switch to alternative chemicals.

19.   Government and public demands for cleaner tailpipe emissions means petrol must be burned effectively in the engine, leaving less harmful emissions to be expelled.

20.   Harmful emissions are less than those from internal combustion engines even if gasoline or other fossil fuels are used in a fuel cell vehicle.