21.   But scientists have gathered increasingly persuasive indirect evidence that such objects exist.

22.   But that hypothesis came from indirect evidence.

23.   But there is indirect evidence that mobility is not high enough in this country to provide an adequate safety valve for those on the bottom rungs.

24.   But the EPA and other scientists contend there is enough indirect evidence that radon is a major cause of cancer at levels found in many homes to take action.

25.   Corliss had deduced the existence of these sea floor vents from indirect evidence.

26.   Even if the cities reveal no monumental traces of strong rulers, all around is indirect evidence of some kind of organizing influence.

27.   Hard proof linking the Shifa factory to terrorism and nerve gas production was elusive, and the indirect evidence that was available was incomplete and open to conflicting interpretations.

28.   Indirect evidence that can be imaginatively interpreted as black holes devouring matter has convinced most cosmologists that they surely exist.

29.   Indirect evidence comes in the form of spectacular close-up photos of Mars, snapped by a robot spacecraft.

30.   Indirect fossil evidence, such as the burrows found by this team, have always been controversial because some natural, non-biological processes can produce similar structures.