How do you say “后退三” in English?

If you are overhauling machinery, you should wear ( ) in order to protect your head

Four strokes consist of suction, compression,( ) and exhaust stroke

We use a manometer to measure ( ).

The fuel pipes and ducts should be blown with ( )

A common ( ) with the fuel pump plungers is oil leakage.

He said that he has turned the main engine one complete revolution with the ( )

We must use ( ) to change sea water into fresh water.

In four-stroke diesel engine, the cycle of events is completed in ( ) of crankshaft.

Are you ready ? Yes, I ( )

Vital components of the engine should be frequently ( )