81.   A lot had changed in a few hours on that January night.

82.   A clock tower chimed, gracefully announcing the hour on this otherwise quiet summer Sunday.

83.   A dancer or musician can suffer for hours on end because he knows why he is suffering.

84.   A few hours on the boat provides some idea of the enjoyment and physical demands that such racing requires.

85.   A result was backups lasting hours on access roads and bridges and through the other tunnels.

86.   A picture of what a certain child with a certain history knows at a certain hour on a certain day.

87.   A Microsoft tech spent more than an hour on the phone helping me tinker with autoexec.bat and config.sys.

88.   A rising productivity rate has meant that workers have produced more each hour on the job.

89.   A typical Esrey workout, five days a week, includes up to an hour on a bike or elliptical trainer and another hour of weight and agility training.

90.   Accidents in which pilots are disabled or killed in planes that then fly for hours on autopilot are rare but not unprecedented.