浮囊

例句：

1. 1. The floating bag floated on the surface of the water.
   这个浮囊浮在水面上。
2. 2. The airbag was designed to protect passengers during a sudden drop in altitude.
   这个气垫是为了在突然下降的海拔中保护乘客而设计的。
3. 3. The buoyant sack kept the cargo from sinking when it was tossed into the sea.
   这个浮囊使货物在被扔进海里时不会沉下去。