61.   Her first reaction had been to laugh, but her second thoughts were more sombre.

62.   People are generally sensitive to many dangers, when drivers approach a sharp bend in the road their natural reaction is to slow down.

63.   Thus, once the reaction is complete, the temperature falls.

64.   Thus, once the reaction is complete, the temperature increases.

65.   The negative sign means the reaction is exothermic.

66.   At one time it was thought that all chemical reactions were exothermic.

67.   For example, combustion reactions are exothermic processes.

68.   On the other hand, we know that combustion reactions are exothermic.

69.   We have seen that for a reaction to be spontaneous must be positive.

70.   Although the intestinal hypersensitivity reaction is highly specific to the priming antigen, the resulting enhancement of permeability is not necessarily antigen specific.