The temperature of boiling water in a steam engine may be high because - (1) there are dissolved substances in water (2) there is low pressure inside the boiler (3) there is high pressure inside the boiler (4) the lire is at very high temperature
(3) there is high pressure inside the boiler Explanation: In the boiler of a steam engine, there is a firebox where coal is shoveled into. The coal is kept burning at a very high temperature, and is used to heat the boiler to boil water producing a high pressure steam. The high-pressure steam expands and exits the boiler via steam pipes into the steam reservoir; the steam is then controlled by a slide valve to move into a cylinder to push the piston.