The art teacher collects them from the students painted pictures.

[Harry]

The art teacher collects them from the students
painted pictures.

A student hands in a blank sheet of paper.
Teacher: "What is that?"
Student: "That's a picture of a cow eating grass."
Teacher: "Where is the grass?"
Student: "The cow ate everything."
Teacher: "Where is the cow?"
Student: "It's gone because the grass was gone.