A boxer moves through the ranks by fighting progressively tougher opponents.

Basically, this system enables players to prepare for the big leagues by playing in progressively tougher minor leagues based around the country.

But Mr. Besharov added: "Young people, especially those who've dropped out of school, have been having a progressively tougher time in our economy.

"It's the same as always, guys getting out fast, but things will get progressively tougher," said Faldo.

It consists of three progressively tougher levels of emission control - called tiers - designed to reduce levels of ozone and carbon monoxide.

The walk got progressively tougher as my leg troubles increased.

These screens combine to form levels, which become progressively tougher.

Visitors are invited to challenge the Beatlebrain computer, whose questions get progressively tougher.

The district later "tweaked its policy so that the penalties get progressively tougher, with the citation coming only after the fifth tardy."

Each bucket calls for progressively tougher tactics, typically with a different group of collectors.