21.   These transition-metaphors operate at several discursive levels.

22.   This will considerably help cash Mow problems for new haulage firms and hauliers still operating at a modest turnover.

23.   Whatever the merits of such proposals, they would operate only at the Margins of the costs that most families incur.

24.   You play against the computer which operates at a chosen skill level so you could have a chance of winning.

25.   The machine was operating at high speed.

26.   The machine can operate at high speeds.

27.   The factory was operating at peak efficiency.

28.   Because these factors operate at the same time the body is adapting to other environmental changes, it may not be clear which physiological changes result from which factors.

29.   Two of the mines, and are operating at a loss.

30.   British mines operate at far greater depth than in America.