11.   But the idea of personalization, some experts acknowledged, has been difficult to sell.

12.   Computer experts acknowledge that identifying the hacker will be a difficult, if not impossible, task.

13.   Even granting some imprecision in the science, most health experts acknowledge a need for new particulate controls.

14.   Even so, the farm policy expert acknowledged that consumers have applauded the quick move, and meat producers dare not criticize it.

15.   Experts acknowledge that the fighting in Afghanistan is likely to be merely an opening skirmish in a long and uncertain war on terrorism.

16.   Experts acknowledge it.

17.   Experts acknowledge that teens are naturally more likely to tell a peer about a problem before telling an adult.

18.   Experts acknowledge, however, that some of the groups in the metropolitan area may have only a few members.

19.   Experts acknowledge that they have yet to determine the most effective procedures for magnetic stimulation.

20.   Fire experts also acknowledge that sprinklers often do not work well in fires where an explosion overwhelms the system.