21.   Physicians must also appreciate the complex interaction among environmental, biological and psychosocial factors.

22.   Scientists suspect that the disease is caused by a complex interaction between genes and the environment.

23.   Staffing levels are set by complex interactions and expectations of investors, owners and top management.

24.   Testing a single chemical on a toxicology chip may miss such complex interactions.

25.   The strength of these poems, however, is their explorations of family life, especially the complex interactions between fathers and sons.

26.   Their shape and movement result from a devilishly complex interaction between the rising plume and the sideways rotation of the planet.

27.   Thinking is a whole complex interaction of neurotransmitters.

28.   Until the complex interaction between the hurricane and capricious steering winds aloft is resolved, the Southeast coast of the United States will remain at risk.

29.   Groupings appear arbitrary, but in themselves they provide a powerful overview of the complex social interactions in these communities.

30.   It does not adequately reflect the complex interactions of oceans, forests and other ecological features in the carbon cycle, White said.