a tough nut in a sentence

Examples

1. It is a tough nut to crack ."
2. Any business that pays 40 percent of its gross revenues is a tough nut to swallow,
3. But Kalicharan is a tough nut to crack.
4. Offaly played almost to exhibition standard at times, although Clare proved a tough nut to crack.
5. This is a tough nut to crack.
6. "Let's face it _ that was a tough nut to crack, " an adviser to Clinton said.
7. Tikrit was a tough nut to crack.
8. The same qualities that make Rembrandt a towering artist also make him a tough nut for connoisseurs.
9. This place is just a tough nut.
10. That's a tough nut to crack for the likes of Red Bullet, Snuck In, and Hugh Hefner.