11.   In most stem cell experiments, scientists must add chemicals to coax the versatile cells, commonly found in human embryos, into becoming the desired tissue.

12.   In molecular terms, the on position amounts to adding chemicals known as phosphate groups to other entities in the cell.

13.   In the now-famous interview with Mike Wallace, he told how toxic chemicals were added to tobacco to enhance the addictive quality of cigarettes.

14.   Many cities are now adding chemicals to drinking water to reduce leaching of lead from the pipes.

15.   Neither of our experts likes to add chemicals, except chlorine remover.

16.   Once you have determined the pH of your pool using your test kit, you can add chemicals to bring it into the preferred range.

17.   Philip Morris Cos. shares fell after a published report alleged that tobacco companies add chemicals to increase the potency of the nicotine a smoker inhales.

18.   Several representatives of the chemical industry agreed with some of the safety board findings, but said simply adding more chemicals to government lists was not a solution.

19.   The chemical is added to lakes and reservoirs, where it kills all the fish by inhibiting their ability to use oxygen.

20.   The competing bills also call for study of tagging ammonium nitrate or adding chemicals that would render it harmless.