Final answer:
The advantage of the Harris and Ullman multiple nuclei model is that it easily incorporates linear and areal physical relief features, allows for multiple secondary business districts, and is applicable to rural areas beyond the urban periphery.
Step-by-step explanation:
The advantage of the Harris and Ullman multiple nuclei model over the Burgess concentric zone model and the Hoyt sector model is that it easily incorporates the depiction of linear and areal physical relief features. In the multiple nuclei model, cities can have multiple secondary business districts, which allows for a more diverse and varied urban landscape. This model is also applicable to rural areas beyond the urban periphery, unlike the other models. Therefore, the multiple nuclei model provides a more flexible and comprehensive understanding of urban structures.