21.   Some environmental groups argue that removing the wood will disrupt the natural cycle of decomposition and promote runoff of sediment that could harm fish.

22.   Smucker said he was sure that the recent dips in the New York Stock Exchange and Nasdaq were part of a natural cycle.

23.   Some are part of the natural cycles of the continent.

24.   The most salient of the natural cycles is the diurnal cycle, with maximum temperatures by day and minimums at night.

25.   The natural cycle of fashion is also a factor in the trend.

26.   The suspicion is that natural cycles of bloom and bust are expanding into a global menace.

27.   This natural cycle helps prevent catastrophic forest fires.

28.   Though burning is part of the natural cycle for lodgepole -- its cones need fire to release seeds -- careful logging can keep lodgepole fires from spreading uncontrollably.

29.   To be sure, economics and the natural cycle of fashion play a part in the trend too.

30.   Unfortunately for human bookkeepers, none of these three natural cycles works as an even multiple of the other.