单项选择题 The space between cylinder liner and jacket is called （）.

单项选择题 The shells are secured by means of bearing caps and studs, the necessary clearance being provided by means of （） of different thickness.

单项选择题 The sequence of parts in a generally used fuel oil supply system for a main engine is （） (1)tanks in the double bottom (2)centrifuges (3)service tank (4)settling tank (5)viscosity regulator