backsiden.臀部
backlogn.积压待办事项;存货;垫底大木头v.积压
backpackern.背包旅行者
backpackers背包客
backpack nuke背包式核弹; 轻型核弹
backpack pump背负式喷雾器
backpack camera背负式电视摄像机
backpack transmitter便携式发射机
backpackers and tourists自助旅行者和观光客
"Every summer they are backpacking in the Rockies"