（） is used for cylinder and cylinder head, the salt water is used for cooling the lubricating oil, the fresh water in the coolers and the charging air in the air cooler.

（） is the removal of exhaust gases by blowing in fresh ...

单项选择题（） is the removal of exhaust gases by blowing in fresh air.

（） is sometimes used for piston cooling since leaks int...

单项选择题（） is sometimes used for piston cooling since leaks into the crankcase would not cause problems.

（） fuel oils （） lubricating oils require treatment befo...

单项选择题（） fuel oils （） lubricating oils require treatment before passing to the engine.