11.   UCLA researchers announced they have identified a substance found in everyone that seems to lead the battle against the virus that causes AIDS, but eventually is defeated.

12.   A balanced system is supposed to be able to identify substances like pollen, animal hair and other allergens.

13.   A final report identifying specific substances takes four to six weeks, Tankenson said.

14.   A dog that identifies those substances responds by pawing and biting at the material, and is rewarded with a game of tug-of-war.

15.   After three years of chemical analysis, the Hairfields identified the substance as terebinth.

16.   But scientists only recently could identify the substance and class it as a banned performance-enhancing stimulant, he said.

17.   Forensic tests identified the substance as sodium hydroxide, the spokesman said.

18.   He would not identify the substance.

19.   Hospital officials believe the gas was caused by a chemical reaction but have not identified the substances that mixed.

20.   It did not identify the substances.