31.   It is a closed system that methodically saps political beings of energy, creativity and even, in very severe cases, their ambition.

32.   It was a closed system.

33.   It proposed going back to the closed primary system for choosing presidential candidates.

34.   It seemed he had erected, concerning literature, a closed system.

35.   Many of the experiments deal with the reclamation and recycling of water and air, and the growth of a food supply in a closed system.

36.   Modern hot-water radiators are less problematic because they are part of a closed system.

37.   No one can argue that the current closed system works to produce a budget on time.

38.   Nonetheless, many people argue that the trend of modern technology is away from closed systems to more open models.

39.   Right now, the dozen or so competing ECNs are closed systems, meaning that they only match orders entered into their own network.

40.   The cost of maintaining the body is rooted in the second law of thermodynamics, which says that closed systems tend to become disordered.