31.   But it also poses a challenge to school districts and lawmakers, since many minority children face barriers to success such as poverty and limited English.

32.   But it could pose a challenge to the Amex, which was close to oblivion before it hit upon ETFs.

33.   But pulling off such a feat from a passenger jet poses challenges, both technical and economic.

34.   But retrieval and privacy still pose a challenge.

35.   But placing the sensor disk on the back of a whale poses a challenge.

36.   But the new openness also poses a challenge to organized labor.

37.   But the prosecution of Milosevic, legal experts said, is not comparable in scope and complexity to other cases and poses a challenge for everyone involved.

38.   But the Internet does pose fresh challenges, it said.

39.   But very tall buildings can pose unusual challenges.

40.   Certainly cyberspace has changed the way people communicate, and it poses challenges for those studying e-mail connections.