11.   If Detroit can build cleaner cars, the aircraft industry surely can build quieter planes.

12.   It will also require expensive investments in cleaner fuels, cleaner cars and new technologies.

13.   Lawmakers and regulators focused on making cars cleaner and more fuel efficient because there were so many more of them.

14.   Or rather, it seems commodified and impersonal, dependent on more efficient appliances, less consumptive houses and cleaner cars instead of altered behavior and wiser choices.

15.   Responding to tough federal mandates, American science and industry have produced cleaner cars, cleaner power plants and cleaner fuels.

16.   Responding to tough federal mandates, science and industry have produced cleaner cars, fuels and power plants.

17.   That would help California because people who settle there from other states would have cleaner cars.

18.   The compromise must still win the approval of foreign-based car companies, but the Japanese manufacturers have generally indicated a willingness to produce cleaner cars.

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

20.   The Prius is the first car of its type to hit the market, demonstrating the technology to make cleaner cars already exists.