Given the task definition and input, reply with output. Given a scientific passage and an answer, generate a question for the given answer.

Passage: Check Your Understanding Define nodes and antinodes. Solution Nodes are areas of wave interference where there is no motion. Antinodes are areas of wave interference where the motion is at its maximum point. Answer: motion
Solution nodes and antinodes are both areas of wave interference, but they differ in the presence of what condition?