11.   Even the tough nuts in the Yankee Stadium crowd were impressed.

12.   Forrest Mars Sr., the man who built the company, was one tough nut.

13.   Going into the campaign, club officials knew they had a tough nut to crack.

14.   Obviously, seasonal cinema is a tough nut to crack.

15.   The Jazz were a tough nut, but the Sonics never cracked.

16.   The Senate, still squabbling over the crime bill, does not represent as tough a nut to crack as the House.

17.   The same qualities that make Rembrandt a towering artist also make him a tough nut for connoisseurs.

18.   With the Israelis and the Palestinians, well, that was always going to be a tough nut to crack.

19.   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.

20.   Pakistan enjoyed territorial supremacy throughout the match against Spain, but found Spanish goalkeeper Bernardino Herrera a tough nut to crack.