knapsack ['næpsæk] n.背包 例句与用法: After a short rest, they took up their knapsacks and went on. 休息了一会儿之后,他们又背起背包上路了。 词形变化: 名词: knapper | 动词过去式: knapped | 动词过去分词: knapped | 动词现在分词: knapping | 动词第三人称单数: knaps | 详细释义: n. (士兵或徒步旅行者用的)背包[C]