21.   Beyond issues of punishment, the U.S. and Japanese publics need to know just what went wrong and what must be done to prevent a repetition.

22.   A Congressional panel has been looking into whether more needs to be done to prevent corporate insiders from trading on private communications from a regulatory agency like the FDA.

23.   A lot of Celtics fans simply did not want to know why Lewis died, or what might have been done to prevent his death.

24.   All he could do to prevent that, of course, was improve his show, by improving himself.

25.   But Law, who sees firsthand the problems that single motherhood brings, says more must be done to prevent unwed births.

26.   But little is done to prevent these hideous miscarriages from occurring.

27.   But what could have been done to prevent the furor?

28.   But they also acknowledge that there is little they can do to prevent the relationship from deepening without damaging larger US.

29.   But, he said, said there was little he could have done to prevent the most recent flare-up.

30.   But what can be done to prevent it?