Possible Clues:

• "Oh, su-u-ure"
• 'Doubtful'
• 'Must be!'
• "Oh, ri-i-ight"
• 'Not surprised!'
• “Su-u-ure”
• 'Jeez, sounds like it!'
• "Oh, su-u-ure!"
• 'Ri-i-i-ight!'
• Expression of doubt