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單項選擇題

The pumps press oil into the cross-head bearing gap when the load on the shell is at its lowest What is the meaning of “its” in the sentence above?（）

A.the cross-head
B.the pumps
C.the shell
D.the load

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單項選擇題

The pumps employed on board ship can be divided into two main categories ie（） pumps and centrifugal pumps.

A.gear
B.nonpositive displacement
C.positive displacement
D.rotary

單項選擇題

The pump has a constant stroke and the amount of fuel delivered is regulated by rotating （） which has a specially arranged helical groove cut into it.

A.the pump cylinder
B.the pump cam
C.the pump plunger
D.the pump miler