Answer
The answer is below.
Work Step by Step
This graph will feature a line with a positive slope until it hits the horizontal line $y=0$, at which point the slope will be 0 for a little while. Then, the slope will be positive again until it hits the horizontal line $y=100$, at which point the slope will be 0 for a little while again. This occurs because when the water goes through a phase change, it does not change temperature while it is at the melting/boiling point: rather, all of the energy goes to melting or boiling the water.
