中央: 1.(中心) centre; middle 短语和例子花园中央 at the centre of the garden2.(最高领导机构) central authorities 短语和例子党中央 the central committee of the party; the party central committee; 中央各部门 departments under
抽真空: creation of vacuumcreed receiving perforatordeaeratedegassingevacuationpick up the suctionvacuatevacuum pumpingvacuum supplyvacuum-extractionvacuum-pumpingvacuumize