单项选择题
In reference to air conditioning, when air attains the maximum amount of moisture it can hold at a specific temperature, it is said to be （）.
A.superheated B.saturated C.condensed D.convected
单项选择题 An axial轴向 piston pump differs from a radial piston pump as the pistons of an axial piston pump are positioned （）.
单项选择题 The usual number of single-acting pistons used in a variable stroke axial-piston pump is （）.
单项选择题 The heat identified by only a change in temperature is known as （）.
