（） may be the first possible cause which makes the engine to lose power or slow down when it is running.

Terri: Derrick, don't you think you should take a vacation? Even one or two days would be fine.Derrick:__________ There's too much work.

When the union purchase derrick is operated, one derrick is positioned over the quayside and the other almost vertically over the （）.

The（）enables water to be blow down or emptied from the boilerIt may be used when partially or completely emptying the boiler.

The guard, fencing or shielding for moving parts or machinery can be removed for repair only when the machinery it belongs to（）

When under maneouvring conditions with the machinery being manually operated the control unit or console should be （）

When under maneuvering conditions with the machinery being manually operated the control unit or console should be

Be careful when you ______ that vase; it will break very easily. ( )

The guard, fencing or shielding for moving parts or machinery can be removed for repair only when the machinery it belongs to（）

Could you show me （）to operate the derrick?

When a tug is pulling on a hawser at right angles to the ship，and the pilot wants to come ahead or astern on the ship’s engine，care must be taken that the pilot（）.

When a crankshaft has to be handled outside the engine, it should be carefully supported in a manner which will avoid （） high bending moments on it.