91.   So far the animals only get sick after very large doses of virus, which makes testing vaccines difficult as enough bugs can defeat any vaccine.

92.   Still, the fight is gearing up to be just as difficult as the Mexico debate.

93.   Such are the trials of starting a company, particularly one as difficult as an airline, where in the age of deregulation failures are the rule.

94.   Still, the fight is gearing up to be just as difficult as the Nafta debate.

95.   Success is often as difficult as failure.

96.   Surprisingly, that can be almost as difficult as getting the fish to bite.

97.   Still, he finds the work not as difficult as movies.

98.   Suddenly, E-commerce executives realized that managing online sales could be as difficult as managing offline merchandising.

99.   That is part of the reason Pitino said life is difficult as a Celtics executive.

100.   That will be politically difficult as unemployment rolls stay high and companies cut their own spending on investment.