Final answer:
Spatial interaction in geography is influenced by complementarity and intervening opportunity.
Step-by-step explanation:
Spatial interaction in geography, which refers to the flow of people, goods, and ideas between different locations, is influenced by several factors. The main factors influencing spatial interaction are complementarity and intervening opportunity. Complementarity is the degree to which two locations have goods or services that complement each other, creating a demand for interaction. Intervening opportunity refers to the presence of alternative opportunities between two locations that may deter or redirect spatial interaction.