11.   These could provide vital clues to climate change.

12.   The letters provide a clue to the answers.

13.   These training shoes could provide a clue to the identity of the joyriders.

14.   Although DNA recognition and binding are important properties of this family, they do not provide obvious clues about the eventual function of the protein.

15.   Even if he did not allow himself to betray his secret directly he might let slip something that would provide a clue.

16.   But the functions provide clues to the mechanisms.

17.   Also, the government releases March consumer price and industrial production reports that will provide clues to possible Federal Reserve interest rate cuts in the near future.

18.   Although there is no record of exactly how the game was played, illustrations on Mayan pottery, the ballfields themselves, and reports by explorers provide clues.

19.   An ambitious and imaginative novel masquerading as a commentary on the Kama Sutra that becomes a literary puzzle in which Nabokov, Joyce and Philip Roth provide the clues.

20.   An analysis of their bones provided clues to the diets of the people.