Related Clues:

• 'That's curious …'
• Competently
• See 21 Across
• Rural water source
• Not ill
• 'Let me think about that …'
• 'I wonder ...'
• "Let me think ..."
• 'Well, let me think …'
• 'Interesting …'
• ''I'm thinking ...''
• ''Very interesting . . .''
• Suitably
• Jack Benny interjection
• ''Let me think . . .''