rucksack

n. /ˈrʌksæk/ B1

背包；旅行包

A large bag carried on the back by walkers or travellers.

仙境例句

A snail carried a tiny rucksack on its back, as well as its shell.

一只蜗牛背上除了壳，还背着一个小小的双肩背包。