11.   Exposure to sun, smog, car exhaust and flooding has produced bubbling and peeling in the oldest segments.

12.   He also drove into the country with a hose before backing out of a plan to kill himself with car exhaust, lawyers said.

13.   He said the trail system would help visitors better enjoy the sights of the canyon, allowing them to smell pine trees instead of car exhaust.

14.   Instead, the company justifies its enthusiasm for hydrogen on the grounds that emission standards for car exhausts are growing ever stricter.

15.   It also makes car exhausts, ships and submarines.

16.   It is a noisy jumble of fatigued cement, car exhaust, cafes, hotels and villas for the well to do.

17.   It is also used in automotive catalytic converters, which remove pollutants from car exhaust.

18.   Ozone is produced when car exhaust, oil-based solvents and gasoline vapors react with nitrogen oxides in sunlight.

19.   Ozone is the main health threat in smog and forms when hydrocarbons from car exhaust and other emissions mix in a chemical reaction fueled by sunlight and heat.