a tough nut to crack in a sentence

Examples

1. Bellegarde proved to be a tough nut to crack and its 1, 000 surviving defenders only capitulated on 17 September.
2. Malaysia should not have any problems with Group A opponents Macau and Mauritius but Thailand will be a tough nut to crack.
3. It looks like a tough nut to crack, " said Santos about the rebels'liberal use of land mines.
4. "Let's face it _ that was a tough nut to crack, " an adviser to Clinton said.
5. Chela, 23rd on the ATP rankings, found Indian ace Paes a tough nut to crack as both sets went to the wire.
6. "I think it's a tough nut to crack, " said Miller, given that few Democrats support private accounts.
7. "I think it's a tough nut to crack, " says Ed Brogan, auto analyst at Jardine Fleming Securities.
8. The fake working title for this show was " A Tough Nut to Crack " to throw off outsiders about the contents of the episode.
9. But how such galaxies came to be is a tough nut to crack, because the galaxies most relevant to that issue are the farthest away.
10. Nelson Pressley, The Washington Post : Musical comedy is a tough nut to crack; there is hardly a rarer commodity in show business anymore.