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单选题
The crankshafts of medium speed engines are almost invariably solid （） from a single piece of steel.
A
forged
B
cast
C
made
D
shrunk
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单选题Crankshafts of medium speed engines are （） from a single piece of steel.A
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never be solid forgedC
almost invariably solid forgedD
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单选题The crankshafts of medium speed engines are almost invariably solid （） from a single piece of steel.A
forgedB
castC
madeD
shrunk
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