Answer:
The next step is to subject the cups to a low temperature environment.
Step-by-step explanation:
If the student wants to analyze whether the earth or water has a higher heat retention, he must submit a sample of soil and a sample of water to a low temperature environment and analyze which of the two samples, takes longer to freeze. In this case, after separating two paper cups with samples of water and sand at room temperature, the student must take these two samples to a cold environment such as a freezer or a bathtub with ice.