51.   Though the study was based on EPA pollution measurements, neither the researchers nor the Environmental Protection Agency could supply a list of pollution levels in American cities Thursday.

52.   And though many ultra-Orthodox men lack a technical background, Torah and Talmud studies are based on logical thinking that comes in handy in computer class.

53.   Most tourism studies are based on conventions and assume one person per room, he said.

54.   Most dinosaur studies are based on bones that have been mineralized into hard stone, or fossils.

55.   She bases her study on societies which are basically patrilineal and bilateral, with traces of matriliny in both.

56.   The Deloitte Touche study was based on national business surveys conducted in Finland, Germany, Netherlands, Sweden, and Britain which actually show widely divergent cost estimates.

57.   The Economy and Environment Program for Southeast Asia and the World Wide Fund for Nature said the study was based on conservative estimates.

58.   The group based its study on field investigations as well as information from relatives and lawyers of the missing people.

59.   The study was based on an analysis of census data by Temple University statistics professor Eugene Erickson, but was not sanctioned by the Census Bureau.

60.   The study was based on analysis of two decades of government data.