Possible Clues:

• Ponder about academic housing to good effect
• Mention too much
• Think long and hard with one of those similar to 7 down about fine
• Be obsessed by
• Assume water has penetrated to linger over
• Keep talking about sport — crushing bore?
• Obsess over
• Be preoccupied with
• Think at length about
• Ponder over water source feeding river