21.   But the sounds seem to linger.

22.   His voice is powerful and dark-hued, but the sound often seemed to be produced at some cost.

23.   Zatorre said the finding was a surprise because his research on brain function has shown that the sound of music seems to activate the right side of the brain.

24.   Adora Jo Altarejos, a flight attendant who was nearer the explosion site, said that the sound seemed to have been caused by a firecracker.