Possible Clues:

• Close to getting through
• "Nearly finished!"
• Nearly finished, or a description of the first words of 20-, 35- and 41-Across
• 'Give me one more minute to wrap this up'
• 'Just about finished'
• "Just one more"
• 'Just one more'
• "I'm just about finished"
• Answering the penultimate exam question, say
• "I'll be finished in a minute"