开: open; turn on; switch on; be ...兑: exchange; convert; cash开多边形: open polygon开堆: reactor start up开多孔使成蜂窝状: honeycomb开断值: drop out value开多圆柱: open polydisk开断旋塞: shut-off cock开垛口: crenelation; crenellation开断容量: switching capacity开躲开: get out of the way开断能力试验: breaking capacity test