11.   The next development was the use of limited motorised vehicles powered by the international combustion engine or electrically driven.

12.   And as if to ensure that, he recommended the retirement of the internal combustion engine.

13.   And use of electric power would foil heat-seeking missiles attracted to internal combustion engines, he added.

14.   Ballard makes fuel cells that generate electricity and are seen as an alternative to combustion engines in cars and industrial equipment.

15.   Before this hybrid appeared, something quite unexpected happened to the old internal combustion engine.

16.   Both the Insight and the Prius are fueled with gasoline and use some of the power from the internal combustion engine to make electricity.

17.   A big thrust for this research comes from car manufacturers looking for a more efficient, less polluting alternative to the internal combustion engine.

18.   A Stirling engine can be substantially more fuel efficient, and less polluting, than traditional internal combustion engines.

19.   After World War II, model-size single-cylinder internal combustion engines appeared, the wonder of the day.

20.   All are hybrids that operate with both conventional gasoline-powered engines and electric power sources and provide three times the fuel economy of internal combustion engines operating alone.