You pull your desk along the floor in your classroom. What does this situation best demonstrate? Potential Energy
An alternate energy source
Gravity
Work

Work

Explanation:

Work can be referred to as the application of a force (F) over a distance (d). In other words, WORK is done when an applied force causes a body to move. Hence, work is a product of the force and the displacement in the direction of the force i.e. W = F × d

In this case, a desk is PULLED along the floor in your classroom, this best indicates WORK because a force (pull) is applied on the desk causing it to move over a distance in the direction of the pull.

a physical change is being made.