单项选择题
Continuous surging of turbocharger can be caused by（） ①crash stop of engine ②increased back pressure after T-Ch ③fouled or damaged turbine nozzle ring
A.all are correct B.②and③are correct C.none of the above is correct D.①only is correct
单项选择题 When occurring a fire in the scavenge air box, the following measures should be taken except for（）
单项选择题 On what do you depend having the air cooler of main engine chemically washed?（）
单项选择题 In a four stroke engine, which process lasts the longest period?（）
