4 - 每天都會跟你到學校，猜猜我是誰？

歡迎登上——Riddle Island 大冒險！ 一起聽線索、猜謎語，找答案，Let’s riddle and go！ 今天，小勇士鄭允甯 來挑戰，到底能不能完成挑戰呢？ 這集的謎題是...

I carry books both big and small,

I’m on your back when you walk the hall.

I hold your lunch, your pens, your stuff,

My zippers close when it’s enough.

I go to school with you each day,

Without me, things would go astray!

What am I?

小朋友，你們覺得今天謎題的正確解答是什麼呢？