11.   In Colorado, the two killers left some clues in the form of computer messages, including death threats, according to Web pages assigned to the boys.

12.   Scientists say that copying machines leave subtle clues on paper that can narrow the search for where the copying was done.

13.   Some buildings are now shapeless piles of stone and rubble, leaving no clue to what might have been destroyed.

14.   The Cowboys had certainly left enough clues on that subject in a first half of yardage dominance that produced just seven points.

15.   The Eagles left clues on how they plan to stop the Rams in their thrashing of the Bears.

16.   The hijackers left few clues from their brief stays in Boston.

17.   Those erratic sales leave few clues about where sales are headed.

18.   But he left some clues.

19.   But the Russians have yet to say whether the vanishing vessel left any clues to the cause of the collision.

20.   It is hard to know what Homer thought of his treatment by critics because he left few clues, Conrads said.