Related Clues:

• Segment covered by a test, perhaps
• One piece of a sectional sofa
• See 61-Across
• Kitchen fixture
• Squad car
• Realtor's sale
• Small group
• Workbook unit
• It's taught and learned
• Fermi or Faraday
• Teacher's instruction
• 'I before E' rule, e.g.
• Squadron
• Military squad
• Apartment