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單項選擇題

A lubricant often has to perform many duties in any situation, in addition to its fundamental job of （）.

A.resisting oxidization
B.reducing friction
C.promoting moving speed
D.developing inertia

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單項選擇題

A level gauge for a tank is to （）.

A.give the pressure
B.give the contents
C.give the shape of the tank
D.give the accuracy level

單項選擇題

A hot air start pipe indicates that there is （）.

A.inefficient cooling
B.a leaking air start valve
C.a clogged drain valve
D.a leaking air bottle

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