11.   The cleaner-burning fuels cost slightly less at the pump, but contain less energy per gallon and are consumed faster.

12.   The company also pledged not to raise fares on some domestic routes for at least two years except for price increases needed to cover inflation and higher fuel costs.

13.   The voracious demand for electricity in California has driven up fuel costs all over the West.

14.   One longtime Harley-Davidson rider was skeptical that an oil-powered bike would ever be popular, even if the fuel someday cost less.

15.   Such flights could give the cash-strapped country another source of hard currency, while saving outside airlines time and fuel costs.