71.   For many chemical reactions performed in a laboratory, the external pressure is simply the atmospheric pressure.

72.   Internal pressure is the pressure of the system acting on its surroundings.

73.   It exists when the pressure is constant throughout all parts of a system.

74.   The molecules are consequently held back in the liquid phase and the vapour pressure is lower.

75.   Since the total vapour pressure is higher than that of either component, the temperature at which the mixture boils is lower than that of either component.

76.   They talk to each other, they commune with each other, and there is a pressure for peace among them.

77.   Pressure on land was fairly slack in the south, whereas in the east there was no shortage of tenants, and the demand for land was maintained.

78.   It is also argued that drug pressure could not be the origin of resistance because halofantrine was not used prophylactically and has a shorter half-life than chloroquine or mefloquine.

79.   The two critical perfusion pressures are those across the coronary and cerebral circulations.

80.   Faced with loss of market shares and firm relocation, there will be downward pressure upon social conditions.