41.   The exchange took place during the cross-examination of Edward Felten, a Princeton University computer science professor.

42.   The exchange Monday took on a personal edge.

43.   The exchange took place in front of the full complement of owners, coaches, club executives and league personnel.

44.   The exchange took place, and the Ambassador was freed.

45.   The exchange will take place Monday, meaning their deadline will come and go with no multiyear contract in place.

46.   The exchange took place in the entranceway outside the food court, and witnesses said about a dozen shots were fired.

47.   The exchanges have taken place in a time-honored arena for mudslinging in Britain, the letters page of a newspaper, The Guardian.

48.   The temperature is lowered because an exchange of heat takes place between the evaporating fog and the outside air.

49.   Their exchange took place with a minute left in the first half and the Lakers ahead by four.

50.   This exchange took place not at the Saturday morning swearing-in ceremony, but a day earlier at the jam-packed Political Americana souvenir shop in Union Station.