101.   But other observers have cast doubt about the extent to which Syria directs the activities of the guerrilla group.

102.   But last month, six Massachusetts Institute of Technology scholars issued a report casting serious doubt on electric cars.

103.   But last year, Nature published a paper by a large team of American scientists that cast doubt on that assertion.

104.   But reports over the weekend cast doubt on that.

105.   But separate interviews with Squier and Eskew cast serious doubt on whether that will be possible.

106.   But shortly after she left, the telecom firm foundered dramatically, casting some doubts on her once stellar resume.

107.   But some scientists have cast doubt on the research of Matser and others.

108.   But the cavalier kissoff of his first effort cast doubt on the sincerity of his second.

109.   But recent experience has cast doubt on how valid these precepts still are.

110.   But recent studies have cast doubt on this assertion.