51.   The trade union movement as a whole would, in the future, face similar challenges to its powers in other industries.

52.   The varied strata of modern society present numerous challenges to surveillance.

53.   There is no serious intellectual challenge to it.

54.   There May be, too, a sottovoce challenge to the received wisdom that it is people who cause desertification.

55.   These changes pose a real challenge to farmers.

56.   They represent a very real challenge to the pub traditional client base.

57.   This departure from the rigid procedures of experimental psychology sets up a radical challenge to the conventional discipline.

58.   This historical work itself represents a strong challenge to some of the premises which underpin the idea of structured dependency.

59.   This was a direct challenge to Urban, who had not been consulted or even properly informed.

60.   True, bolder challenges to orthodoxy, especially when they touched upon the role played by the party, provoked fierce resistance.