a diagram of a river food web a graph of the amount of rainfall on a lake a picture of fog covering a mountain valley a model of a stream flowing down a hillside
I gave my students this multiple choice question: A student prepared a presentation to show how water changes the surface of Earth. Which presentation would best demonstrate how water changes the surface of Earth?

Only one answer is correct among these 4 choices:
- a diagram of a river food web
- a graph of the amount of rainfall on a lake
- a picture of fog covering a mountain valley
- a model of a stream flowing down a hillside

Could you tell me which one is correct?

a model of a stream flowing down a hillside