Answer
See answer.
Work Step by Step
Consider standing waves. The locations of nodes and antinodes are fixed in space. If you stay at one spatial location in the medium, you will observe the same amplitude at all times. As the question says, standing waves can be described as “interference in space”. As you move to different points in space and make observations, the type of interference changes from fully constructive (antinode) to fully destructive (node).
Consider the waves created by beats. The locations of nodes and antinodes are not fixed in space. If you stay at one spatial location in the medium, at a certain point in time, the medium will have zero displacement from equilibrium (node). However, if you merely wait half of a beat period, then that point in the medium will move to its maximum displacement from equilibrium (antinode) As the question says, beats can be described as “interference in time”. As you move to different points in time and make observations, the type of interference changes from fully constructive (antinode) to fully destructive (node).