Bedplates are the （） of the engine, without the support of which the shaft alignment in particular, and engine structure as a whole, would inevitably be lost.

Because the castings of smaller engines are not so big ...

单项选择题Because the castings of smaller engines are not so big and heavy, （） and cylinder block may be made in one piece.

Bearing knocks are likely to occur from （）.A.less clear...

单项选择题Bearing knocks are likely to occur from （）.

Be sure to make the engine turn by （） before starting a...

单项选择题Be sure to make the engine turn by （） before starting and after stopping .