[单选题]/[A/] for/[B/] up/[C/] off/[D/] on
[单选题]41 A turn up B show off C come on D go away
[单选题]A. onB. outC. overD. off
[单选题]_________[A] off [B] behind [C] over [D] along
[单选题]The piston moving up and down keeps the crankshaft ().A . to revolveB . revolvedC . revolvingD . to be revolved
[单选题]A. around B over C on D up
[单选题][A] upon [B] back [C] off [D] away
[单选题][A] onto [B] against [C] off [D] along
[单选题][A] over [B] out [C] off [D] away
[单选题]The piston moves up and down, thus causing the rotational movement of the()A . crankshaftB . connecting rodC . cross-headD . main beating