n.（指登山者、步行者使用或背小孩时使用的）背包, （有轻金属框的）箱形背包
backpack的复数

原形：backpack复数：backpacks

He slung his backpack over his shoulder as he prepared for the hike.
他准备远足时，把背包甩到了肩上。
The backpack was stuffed with books, making it quite heavy to carry.
背包里塞满了书，背起来很重。
She rummaged through her backpack looking for her keys.
她在背包里翻找钥匙。
Don't forget to pack a water bottle in your backpack for the trip.
别忘了在旅行中给背包里放一瓶水。
The children were excitedly showing off their new backpacks on the first day of school.
开学第一天，孩子们兴奋地展示着他们的新背包。
He unzipped his backpack and pulled out a map to check their location.
他拉开背包的拉链，拿出一张地图查看他们的位置。
Make sure your backpack has a comfortable strap so it doesn't hurt your shoulders.
确保你的背包有舒适的背带，这样就不会伤到肩膀。
The hiker's backpack contained all the essentials for survival in the wilderness.
远足者的背包里装有野外生存的所有必需品。
She neatly organized her school supplies in her backpack before leaving home.
出门前，她将学习用品整齐地放在了背包里。
After a long day at school, he threw his heavy backpack onto the floor with a sigh of relief.
经过一整天的学习后，他叹了口气，将沉重的背包扔在了地板上。