Possible Clues:

• Many intro-level class instructors, for short
• See 6-Down
• Profs' test graders, perhaps
• Lecture hall helpers, for short
• The two in a Brit's farewell
• U. 2's?
• Prof's graders, perhaps
• "___ in turkey" (elementary lesson)
• HS helpers
• Aides at 29-Across (Abbr.)