21.   I think I understand the reason.

22.   It takes some detective work to understand the reason for this apparent fare spat between Eagan, Minn.-based Northwest and Houston-based Continental.

23.   Lehner said it would be weeks before the officials would understand the reasons for the failure.

24.   No one understood the reason for his crestfallen demeanor until he disclosed that a close friend had died on Thursday.

25.   Policies, not poetry, save woods, but poets understand the reason for them.

26.   Reading it, one can understand the reasons for the neglect.

27.   Scientists do not fully understand the reasons for the disparities between blacks and whites, and the study did not provide an explanation.

28.   She voted against the proposition, but understands the reasons behind it.

29.   Some reservists in Bosnia have been assigned tours of more than six months, and many say their families and employers do not understand the reasons for their absence.

30.   Some, like retired surgeon Mohammad Cheema, are against the attacks but understand the reasons behind them.