单项选择题
The three basic parts of any eductor are the nozzle, the suction chamber, and the （）.
A.injector B.compressor C.diffuser D.siphon
单项选择题 （）, the engine must be stopped immediately.
单项选择题 Grind the （）.
单项选择题 Which of the following can be obtained by means of an indicator card?（）
