Related Clues:

• Cause of a senior's stress?
• Probe
• Physical, e.g.
• More than a quiz
• Breast ___
• Word with eye or taste
• Kind of pattern or pilot
• Cause of a class struggle?
• New driver's hurdle
• Entrance requirement, perhaps
• See 80-Across
• Course climax
• Academic hurdle
• Academic challenge
• Class act