Related Clues:

• Challenge
• Lot to ask
• Difficult task
• Tough thing to fill
• Tough request
• Difficult assignment
• Hard thing to fill
• Hard-to-meet requirement
• Really big job
• Challenging request
• Formidable request
• That's a lot to do
• Hard thing to pull off
• Formidable task
• Lofty command - that's a difficult task