Avodah Zarah 31 - Shabbat July 19, 23 Tamuz

If one entrusts items to an idol worshipper for safekeeping, should there be concern that they might have substituted their own items in place of the originals? How many seals are required on the item to eliminate suspicion of tampering? Can one purchase wine from the Cutim? Is there a concern that idol worshippers may have come into contact with the wine, rendering it prohibited? Why is beer produced by idol worshippers forbidden?