单项选择题
The minimum speed an engine must attain before ignition can occur depends upon （）.
A.the type and size of the engine B.the condition of the engine C.ambient temperature D.all of the above
单项选择题 For a given size engine, the two-stroke/cycle diesel engine will deliver more power than a four-stroke/cycle diesel engine because （）.
单项选择题 Lube oil cannot be efficiently filtered if its （）.
单项选择题 In using reduction gears to obtain efficient propeller speeds, （）.
