11.  In some European cities, addicts can exchange used syringes for clean ones at local police stations without fear of prosecution or harassment.

12.  One afternoon last week, a young Aborigine woman in a Reebok sweatshirt walked to a white van, where she exchanged a used needle for a clean one.

13.  She is a firm believer that skaters can sometimes learn more after skating a rough program than a clean one.

14.  The dirty dishes in the kitchen seem to outnumber the clean ones you started with.

15.  The results showed that parasites killed more M. lapponica at polluted sites than at relatively clean ones.

16.  They also attacked the president for his decision to not fund needle-exchange programs that allow drug users to swap used needles for clean ones.

17.  They make photocopies or computer printouts and post a clean one on the refrigerator each week.

18.  Watters strongly advocated programs that allowed drug users to exchange used needles for clean ones.

19.  We took dirty babies with sores and turned them into clean bandaged ones.

20.  Whoever gets the credit, there is little doubt that the process is a clean one.