Final answer:
The spread of Islam in two regions before 1450 resulted in the establishment of Islamic religious institutions, providing consistency and facilitating movement within the Islamic world.
Step-by-step explanation:
One similarity in how Islam affected society in two regions where it spread before 1450 is the establishment of Islamic religious institutions. As Muslims migrated to new lands, they brought their familiar religious institutions with them, providing a level of consistency for local people and travelers. This facilitated movement and exchange within the Islamic world and helped to unify Muslims as individual polities rose, fell, and were replaced.
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