11.   But the constant presence of cigarette smoke makes the body produce far too much of the elastase, which destroys the lung cells it is trying to rebuild.

12.   But they have their hands full at the malls, where they are a constant presence.

13.   Death has been a constant presence, and as they approached early manhood many sensed it bearing down on them.

14.   Dominick Dunne has been a constant presence at the O.J. Simpson trial, which he is covering for Vanity Fair magazine.

15.   Dengue fever is now a constant presence in Puerto Rico, with occasional epidemic flare-ups.

16.   Drug and alcohol abuse is a constant presence in child maltreatment.

17.   Drug sales are common, and the police are a constant presence.

18.   Elaine remains a constant presence through a hilarious series of inopportune phone calls, in which she forms a surprising bond with Hammond.

19.   Even the audio adds to the illusion with the constant presence of the sounds of birds and bugs.

20.   George Steinbrenner has not been the constant goading presence he once was, but newcomers notice that he does set a certain tone.