Which occurs in what?

"Which occurs in what?" is about figuring out where something happens based on what it is.

Imagine you have a bag full of different toys, cars, blocks, balls, and dolls. Now imagine your friend asks, "Which toy goes where?" You look at the room and see shelves: one for cars, one for blocks, one for balls, and one for dolls. So you sort them out, which toy goes on what shelf.

That’s like "which occurs in what?", it's asking which thing happens inside another thing. Like, if you have a red ball and a blue ball, the red one might be in the basket, and the blue one is in the box. So we say "the red ball occurs in the basket," and "the blue ball occurs in the box."

When we use this idea, it helps us understand how things are organized or grouped. Just like you know where to find your favorite toy, maybe it's always in the same place, we can figure out where something is by knowing what it is.