Well, I don't know, see, I was sweeping the classroom...

[She did, in fact, do so, to show what she had done, in case there was confusion]

But there suddenly was a lot of paper on the floor, even in places I had already swept, most of them near her! She pointed out that paper comes from trees so there probably was a tree somewhere that lost them.

I don't know why the tree was stalking her and I didn't see it, it must be very sneaky. It's a bit scary.