51.   MacDonald said none of the other cases was life-threatening, and the day care center was closed as officials tried to determine the source of the contamination.

52.   Lungu said the cars were being investigated to determine the source of the supply.

53.   Marques said city health officials were carrying out chemical tests at several local water towers to try to determine the source of the infection.

54.   Officials have not determined the source of the anthrax that killed her.

55.   Officials said they would ask volcanologists to study the emissions and determine their source.

56.   Scientists at Belarusian Academy of Sciences were analyzing the materials to help determine their source.

57.   She said the Department of Environment was still conducting investigations to determine the source of contamination.

58.   Several dozen medical investigators are working at the school to determine the source of the illness, the spokesman said.

59.   She said more tests were needed to determine the source of the contamination.

60.   The false names, addresses and telephone numbers made it difficult to determine the source of the bogus e-mails, prosecutors said.