a baffling problem.
a problematic situation at home.
a rugged competitive examination.
a tough all-weather fabric.
a tough break.
a tough character.
had hard luck.
he was feeling tough after a restless night.
I faced the knotty problem of what to have for breakfast.
it was a tough job.
it's a tough life.
my throat feels bad.
she felt bad all over.
some plastics are as tough as metal.
sturdy canvas.
sturdy steel shelves.
the competition was tough.
the more ruffianly element.
the rugged conditions of frontier life.
the tough bottoms of his feet.
tough street gangs.