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單項(xiàng)選擇題

The main bearing shells often have a thin （） of lead or indium to provide a layer giving protection against corrosion.

A.flange
B.flash
C.plate
D.sheet

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單項(xiàng)選擇題

The main bearing shells are made of steel with a lining of bearing metal which may be white metal, copper-lead or aluminum-tin alloy What is the meaning of “which” in the sentence above?（）

A.main bearing shells
B.main bearing
C.steel
D.bearing metal

單項(xiàng)選擇題

The main bearing metal is a lining （）.

A.inside the bearing
B.outside the bearing
C.covering the crankshaft
D.none of the above

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