3 - 又大又可以寫東西，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，小勇士鄭允樂 來挑戰，到底能不能完成挑戰呢？ 這集的謎題是...

I’m big and dark and hang on the wall,

The teacher writes on me for all.

With chalk in hand, the lines appear,

I help you learn what’s written here.

At the end, I’m wiped so clean,

Ready for the next day’s scene!

What am I?

小朋友，你們覺得今天謎題的正確解答是什麼呢？