51.   Many employees work countless hours of unpaid overtime.

52.   Minerals giving very low intensity emission, such as quartz grains, required many minutes or even hours of exposure with fast films.

53.   Once they had settled when and where, he climbed back into bed, hoping to catch another hour of sleep.

54.   Or, asking your employer if you can change your hours of work so that you can take advantage of cheap rate travel.

55.   Our cruising grounds afford an almost constant sailing breeze and long hours of clear sunshine throughout the summer months.

56.   She savoured her few hours of freedom.

57.   She turned herself over in her bed, and snuggled down for an extra, self-indulgent and rare hour of sleep.

58.   The attack happened in the early hours of Sunday morning.