three pair三对threenum.三n.三；三个adj.三个的three-dimensional activity三维活动three-stage air compressor三级空气压缩机three- phase rectification三相精馏three river sources District三江源区threephase slip-ring motor三相滑环式电动机three-layer structure mode三层结构模式three dimensional pantograph立体刻模机three-dimensional analysis立体分析, 三度分析three dimensional earthquake三维地震Three-level Cost Accouting三级成本核算

1. The company occupies three floors block.
   这家公司占用了办公室大楼的三层楼房。
2. Double-helix staircases link all three levels.
   双螺旋楼梯将上下三层连接了起来。