Final answer:
The parts of the graph that represent an object moving at a constant, positive acceleration are W and Z.
Step-by-step explanation:
The graph of acceleration vs. time would show a constant positive acceleration when the graph is a horizontal line at a non-zero positive value.
In this case, the parts of the graph that represent an object moving at a constant, positive acceleration are W and Z.
This can be determined by analyzing the graph and looking for segments where the acceleration is constant and positive.