单项选择题
A.pressure gauges
B.stretch gauges
C.thermometers
D.bridge gauges
单项选择题 The cooling water temperature （） over a period of 8 hours, and then shut down.
单项选择题 The cooling water jacket is common to all the cylinders but there are often （） to ensure that each cylinder receives the right amount and flow of water.
单项选择题 The cooling water is in direct contact with the outer surface of the liner as a result of which it is termed a （）.