来自吕书志的问题
inwhich中的which指什么?apumphadcomeintouseinwhichexpandingsteamraisedapistoninacylinder,andatmosphericpressurebroughtitdownagainwhenthesteamcondensedinsidethecylindertoformavacuum.
inwhich中的which指什么?
apumphadcomeintouseinwhichexpandingsteamraisedapistoninacylinder,andatmosphericpressurebroughtitdownagainwhenthesteamcondensedinsidethecylindertoformavacuum.
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2020-12-23 07:37