flotation process浮选法
air flotation空气浮选;充气浮选
2.If you can't swim well but you need to cross a large body of water, you can use your pants as a flotation device.
如果你游泳不好,但你需要游过一大片水域,你可以用裤子作为漂浮。
4.They'd assigned me a "swim angel" with a flotation device in case I had trouble, but I left her behind.
他们给我分配了一个“游泳天使”,准备了救生设备以防我遇到麻烦,但我把她甩在了身后。