单项选择题
A.a setting tank
B.a service tank
C.a head tank
D.an expansion joint
单项选择题 The working cycle of a four-stroke diesel engine consists of four events:（） (1) compression (2) expansion (3) exhaust (4) suctionThe correct sequence is
单项选择题 The work fuel does in each working cycle can be obtained by taking the （）.
单项选择题 The words such as quantity, grade, viscosity and specific gravity should be in the （）.