Final answer:
Typically, one Torah scroll is read during Shabbat services, but special occasions may require reading from two or more scrolls to accommodate holiday-specific readings.
Step-by-step explanation:
The number of Torah scrolls read from on Shabbat can vary depending on the occasion. Typically, one Torah scroll is used during a regular Shabbat service. However, there can be occasions when more than one Torah scroll is read. For example, during a Shabbat that coincides with a special holiday like Sukkot, Passover, or Shavuot, a second Torah scroll may be used to read a section pertaining to the holiday. Another instance is on Simchat Torah when all the Torah scrolls can be taken out, and portions of each may be read. The carrying out of the Torah scrolls, the reading, and the care taken in their transcribing all highlight the importance of the Torah in Jewish religious practice, a tradition that was especially preserved during times of exile when being able to take one's religious practices along was crucial for the survival of Jewish identity.