The city's researchers first turned to the usual suspects, such as air pollution, pollen and mould.
The answer is, the usual suspects: greed and cowardice.
The usual suspects will, of course, denounce such ideas as irresponsible.
Expect the "usual suspects, " including past champions, to be contending for this year's title, said Mitch Seavey, winner of the 2004 race. "Some of the younger guys are going to be a factor."