91.  The difficult part is deciding whether to use it.

92.  The difficult part is the last part for Drew Bledsoe.

93.  The difficult part for the Jets and Giants is that the level of expectation surrounding both teams has skyrocketed.

94.  The difficult part was doing it.

95.  The difficult part, as he would later learn, would be convincing others.

96.  The most difficult part about being here, the astronauts said, is not the living conditions, but Russian grammar, in which they are drilled every day.

97.  The most difficult part is learning the new terminology.

98.  The most difficult part of marathon driving is the recovery.

99.  The most difficult part of the job is dealing with all the personalities.

100.  The most difficult part of this exercise was sacrificing a perfectly good chocolate bar.